Iano's backfill

The Delivery of Design and Construction Services

AGC-AIA Dispute Represents Deeper AEC/O Rifts (Cadalyst, Oct 25, 2007) discusses how changes in methods of project delivery, such as building information modeling, are leading to changes in the traditional roles of the designer and builder--changes that do not always come easily.

The upcoming 5th Edition of Fundamentals of Building Construction (due Fall of 2008) will have an expanded discussion of the roles of the building and construction manager in the construction of buildings.

More Info
Building Futures Council
The AGC's BIM Initiatives and the Contractor's Guide to BIM (AEC Bytes)

Carbon Neutral Building Design

Green Building Studio Inc. has launched version 3 of their Green Building Studio web-based software for analyzing the energy impacts of alternative building designs. According to GBS, in less than 3 hours you can register your project, submit your BIM building model, review results with your consultants, and tune building parameters to optimize the whole building energy use. The software addresses carbon neutral building, US EPA Energy Star scores, water usage, daylighting, natural ventilation, and other factors.

The BuildCarbonNeutral calculator estimates the C02 emissions of a proposed building based on its size, method of construction, and location. Jointly developed by Mithun Architects and the Lady Bird Johnson Wildflower Center, the tool purportedly:

estimates the embodied energy and subsequent carbon amounts released during construction. The measurements account for building materials, processes and carbon released due to ecosystem degradation or sequestered through landscape installation or restoration.

Accessibility and the IBC

The June 2007 Building Safety Journal is devoted mostly to accessibility regulations and the International Building Code, including discussion of:

• The 2006 IBC and 2003 ICC/ANSI A117.1 accessibility standard have been accepted by the US Department of Housing and Urban Development as a safe harbor for meeting HUD's Fair Housing Act design and construction accessibility guidelines.
• The US Access Board Committee's Courthouse Access Advisory Committee has issued a written report providing guidelines for accessible design in courthouses.
• The US Access Boards ADA and ABA standard continues to move toward adoption by the DOJ. (But the discussion of the application of various Federal agency guidelines leaves this author scratching his head.)
• Accessible design for new stadiums
• Elevators and accessible egress in tall buildings discussed, including ongoing study of elevator-assisted egress
• Theater accessibility
• Accessibility of sinks within work areas
• Differences among adoption of accessibility at the state level

For those dealing with these design issues, this issue of Building Safety Journal is worth a look.

Standards: New (costly?), New (better?), and Needed(?)

ENR's Third Exit Stair Could Make Highrises Too Costly to Build (June 4, 2007) reports on the adoption of more stringent life safety requirements for tall buildings in the 2007 Supplement to the International Building Code. Both the Building Owners and Managers Association International and the American Institute of Architects oppose as too costly a new requirement for buildings taller than 420 feet to have at least 3 independent exit stairs. Other changes to tall building requirements in the 2007 Supplement, all coming in the aftermath of the 9/11 attacks on the World Trade Center Buildings in New York City, include:

• protected fire service elevators and lobbies
• photoluminescent pathway markings in exit stairwells
• inspection and greater strength requirements for spray-applied fireproofing.

Proposals for progressive collapse resistance, increased  exit stairway enclosure integrity, and requirements for a a building's ability to burn without collapse were rejected. See the ICC's Code Development page for more information about that organization's code development process and the adoption of these new requirements.

In the same issue, Energy-Efficiency Guidelines Would Be National Model reports on the American Society of Heating, Refrigerating and Air Conditioning Engineer's (ASHRAE) ongoing development of Standard 89, an enhanced building energy efficiency guideline. Standard 89, now open for comments, is intended to reduce building energy consumption by 30% in comparison to ASHRAE's long-recognized Standard 90, and is being touted as a national standard for achieving LEED certified optimized energy performance. See ASHRAE's Advanced Energy Design Guides page for more about this organization's enhanced energy performance guidelines.

Lastly, Innovative Mix with Fly Ash is Still Not Widely Used describes a concrete mix composed of lime, portland cement, and fly ash developed by Nai C. Yang of the New Port Authority 38 years ago for use in airport runway construction. The mix is claimed to provide superior concrete and a reduction in environmental impact (due to reduction in cement content and, consequently, reductions in C02 emissions). However its broader use in airport construction has been hampered by unfamiliarity and a lack of standards for its production.

Green Construction News

Greenhouse (Eco-Structure, May/June 2007) reports on the National Association of Home Builder's (NAHB) February announcement of the development of a new residential building sustainability standard. To be produced in cooperation with the International Code Council, the new National Green Building Standard will be an ANSI certified consensus standard and will replace NAHB's current Model Green Home Building Guidelines.

Unlike the Guidelines, the new standard will be administered nationally, rather than at the local level, and will apply not only to single-family residences and townhouses, but to apartments and other types of multi-unit residential construction as well. Three levels of certification will be offered, Bronze, Silver, and Gold.

The standard is planned for release in February, 2008.

Trends and Challenges in Green Building (Building Safety Journal, April 2007) discusses coordination between sustainable design standards and building codes.

Historically, building codes have focused  on life-safety concerns and regulated construction so as to achieve immediately tangible benefits (such as higher resistance to fire or improved egress). More recently, some code requirements, such as energy efficiency in buildings, have been developed with the intent to provide benefits in the longer term and extending beyond the immediate users of the building.

Outside of energy efficiency regulations, coordination between long-term sustainability goals and building codes has been limited to date. Green building techniques relying on alternative building practices (for example, rammed earth construction) are frequently not addressed in the model codes. Green building programs, such as USGBC LEED or GreenGlobes, were originally formulated and continue to operate outside of the building code regulatory infrastructure.

Efforts to improve coordination between the model codes and sustainability initiatives include:

• Newer provisions within the codes themselves recognizing sustainable design practices such as insulated concrete formwork construction, unvented conditioned attics, waterless urinals, and greywater recycling systems
• Incorporation of energy efficiency standards meeting green building assessment criteria into the building codes, such as the proposed Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings (ASHRAE/USGBC/IESNA Proposed Standard 189)
• The National Green Building Standard for residential construction, currently under development by the NAHB and the ICC (see above)
• Establishment of the USGBC committee Greening the Codes
• ICC's Industry Advisory Committee's comparison of Green Globes and LEED building assessment criteria (see Reports, IAC Task Group Report Green Buildings (March, 2007)

More Info
NAHB Research Center National Green Building Standard home page
ICC Green Building page

Model Code Cooperation Falters

Reversing previous reports, the International Code Council (ICC) has announced the suspension of efforts for the joint development of a single set of coordinated mechanical and plumbing codes in place of the competing codes currently published by itself and the International Association of Plumbing and Mechanical Officials (IAPMO). According to the ICC's September 1 press release, reconciliation of the two organizations' different code development processes was the major stumbling block. 

As this author understands it, the ICC accepts code change proposals from any interested party, but limits participation in final voting to governmental representatives (that is, ICC member building code officials). IAPMO permits a broader spectrum of participants, including consumers, governmental officials, and industry/manufacturer representatives, to have a say in final decision making. The ICC views their change process as less subject to the influence of special interests. Whereas IAPMO claims their process protects against any one group gaining undue advantage.

Regardless of the merits of either organization's claims, this author views the breakdown of this joint development process as a setback for the design and construction industry.

Really Fast-Built Houses

Record-Breaking Concrete--22-minute set (Concrete Construction, November 2005) reports on the 2 Hour House project in Tyler Texas. According to the article, the goal of the project was to construct a home from the ground up in less than two and one-half hours. Two  teams competed to complete 2160 sf homes including concrete slab on grade, three bedrooms, two baths, two-car garages, and full landscaping in the allotted time. Of particular note for readers of this particular publication, was the specially formulated concrete with a 22-minute set time.

Increasing Model Codes Cooperation

The International Code Council, authors of the International family of codes, has announced an agreement for closer cooperation between the ICC and the International Association of Pluming and Mechanical Officials (IAPMO), the authors of the Uniform Mechanical and Plumbing Codes. According to the announcement:

The parties intend to explore a joint venture that would allow them to work cooperatively to develop successor codes to the Uniform and International Plumbing and Mechanical Codes...The parties intend, in order to promote the public interest, to work to identify a system to allow them jointly to develop a single set of coordinated successor codes to the Uniform and International Plumbing and Mechanical Codes.

In related news, it appears to this author that the upcoming 2006 edition of the International Building Code will also more directly reference the National Electrical Code, the dominant national model electrical code produced by the National Fire Protection Association (NFPA). See the ICC's 2004/2005 Code Development page for more information on the upcoming 2006 Codes.

See also California Backpedals on NFPA Building Code for news regarding that state's recent decision to adopt the International family of codes.

For those of us (this author included) rooting for a unified, consistent set of national model building codes, these are promising developments.

Comparing Building Code & Federal Accessibility Regulations

The International Code Council's Accessibility web page is a good source of information about building accessibility regulations. It links to information about requirements contained within the International Building Code (IBC) itself, as well as to how the IBC's requirements relate to Federal regulations such as the Americans With Disabilities Act and others. For anyone trying to learn more about these various requirements and how they relate, this page is one good starting point.

This author found the following links particularly useful:

• Federal laws related to accessibility provides an overview of the various Federal laws that impact on building accessibility, including the Access Board, the Architectural Barriers Act, the Fair Housing Act, the Americans With Disabilities Act, and the ADA-ABA Accessibility Guidelines. It also links to more information on these various topics.
• My state has adopted the IBC: What does that mean for compliance with ADAAG?, an article first published by the ICC in 2004, discusses the relationship between IBC and Federal ADA access requirements. Discussion includes how closely different versions of these two sets of regulations compare, and where there are significant differences.
• 2003 International Building Code meets FHA accessibility requirements discusses IBC regulations in relation to requirements of the Federal Fair Housing Act, noting in particular HUD's acceptance of the IBC's requirements as satisfactory to comply with those of the Act.

More Info
New Accessibility Guidelines Coming
Finding Your Way Through Accessibility Regulations

Digital Building Modeling & Facilities Design

Build It First Digitally (ENR, October 10, 2005) describes General Motors Corporation's use of 3-d digital modeling to fundamentally change the design and construction of two manufacturing facilities: the 2.4 million square foot Lansing Delta Township vehicle assembly plant and the 442,000 square foot addition to the Global V6 engine plant in Flint, Michigan.

In the case of the Flint plant, benefits attributed to the new techniques include a 24-week reduction in the typical 85-week construction schedule, completion of construction 5 weeks ahead of schedule, and zero change orders for building component interface conflicts (i.e., conflicts between piping, ductwork, structure, and other such elements). Michael Neville, vice president and project principal at Ghafari Associates, the architectural/engineering technology integrator on the project states, "In 26 years I have never seen a project run with more collaboration and be so simple."

According to ENR, the design process worked as follows: At the end of each week, updated design data was delivered from design subcontractors to the technology integrator. Over the weekend, this data was integrated into the shared building model, and collision detection routines were run to identify physical conflicts between elements. On Mondays, the design team would meet to review and resolve conflicts. (In initial runs, as many as 3000 collisions were detected.) Once design was complete and all conflicts resolved, the building model was "locked" and all parties agreed to construct the building according to the design model.

Other impacts of a building information model-centric design process included:

• Loosening of GM's traditionally rigid design software standards to accomodate the specialized building information modeling tools used on the project
• Elimination of paper progress submissions at 30%, 60%, and 90% design completion
• Use of the building model for the development of $5.5 million in value engineering savings at 90% completion of design
• Gains in construction efficiency with greater reliance on off-site prefabrication of assemblies, reduced construction waste, and reductions in on-site worker forces

Moving forward with future projects, GM predicts savings of 3% to 5% per project through elimination of systems interference alone, not including additional savings due to reduced construction time.

For more on related topics, see other articles in this site's Innovations In Building Design & Delivery category.

Canada National Codes Set For Update

2005 National Construction Codes available in September (Construction Innovation, June 2005) reports on the upcoming publication of new versions of Canada's model construction codes.

Along with updates to address technical advances, these codes will also have a new three-part organization:

• Division A will include compliance options and information on new elements called objectives and functional statements.
• Division B will provide the “acceptable solutions” (consisting of the 1995 Code provisions updated with technical changes).
• Division C will contain consolidated administrative provisions.

With the recent significant changes in US model codes, it's been easy to forget that Canada also has it's own set of model building codes, the National Construction Codes, including the National Building Code of Canada (NBC), National Fire Code of Canada (NFC), and National Plumbing Code of Canada (NPC). For more on these codes, see Canada's National Code Documents web site, or look for  future commentary on this site once the new code documents become available.

NIST Continues Progress on WTC Report

Report on Trade Center Collapses Emphasizes Damage to Fireproofing (April 5, 2005, New York Times) reports on the National Institute of Science and Technology's (NIST) April 5, 2005 public progress briefing. Some of the Institutes's findings include:

• Structural damage caused by the impacts of the airplanes in and of themselves was not sufficient to have caused the tower collapses.
• The towers collapsed when the structural frames were further weakened by the fires that followed the plane impacts.
• The structures were rendered more vulnerable to fire when fireproofing was dislodged from the structural steel members by the plane impacts.
• Though jet fuel contributed to the initial fires, the fires were mainly fueled by building contents, and to a lesser extent by aircraft contents.

The article also states that had the towers been full at the time of the attacks (they were each only about 1/3 occupied) roughly 14,000 persons could have died due to the greater time required to evacuate the larger numbers of occupants from the buildings.

Critics Blast Findings of Federal 9/11 Study (April 18, 2005, Engineering News Record) reports on critics who characterize the NIST study as expensive ($16 million) and misguided.

Jon D. Magnusson of Magnusson Klemencic Associates, Seattle, is quoted criticizing NIST for proposing building code changes based on the study of "one building that was unlike any other, for a single vent that had never happened before." Magnusson does not believe the NIST recommendations will lead to actual increases in public safety. Others echo similar concerns, citing a lack of analysis to determine the degree to which recommended safety enhancements can save lives, or characterizing recommendations as based on speculation.

Additional related articles available from ENR include:

• WTC Report Triggers Debate Over Safety (ENR 7/4/2005)
• Recommendations Gain Qualified Support (ENR 7/25/05)
• A New Era for Fire Protection and Life Safety (Architecture Record, 8/2005)

NIST will be publicly releasing its Draft Report and Recommendations on June 23.

More Info:

• Previous articles on Iano's Backfill related to building safety in general and the World Trade Center disaster in particular
• NIST's WTC web site

California Backpedals on NFPA Building Code

California Building Standards Commission Withdraws 2003 Code Recommendations (International Code Council [ICC] press release, March 16, 2005) reports that the California Building Standards Commission has voted to rescind its previous endorsement of the NFPA building code as the model on which to base future editions of the state's building code. This vote follows the Commission's Coordinating Council recommendation [pdf] on March 8 in support of the ICC model codes. The Coordinating Council's recommendation identified significant monetary costs and technical hurdles in proceeding with adoption of the NFPA model code. These decisions essentially clear the way for the State's eventual adoption of the ICC codes.

In this author's opinion, this is good news for the design and construction industry. A single set of coordinated model codes used as the basis for building regulations throughout the US is a benefit to the design and construction industry and as well as to the public.

In Search of New Materials

Entrepreneurial Curators Seek Innovations (Architecture Record, 12.04), discusses emerging resources for designers seeking materials that are new, sustainable, or otherwise outside the boundaries of what is conventionally available in the construction industry:

Materials ConneXion, provides an on-line database of information concerning new materials and manufacturing processes from manufacturing, building, and other industries. It also has on-site libraries of over 1400 materials samples in New York, Milan, and Cologne.

The Chicago-based Inventables, targeted mainly at industrial designers, publishes a quarterly publication DesignAid, which includes actual materials samples, a printed design guide, and access to its on-line database.

Materials Monthly, by Princeton Architectural Press, is scheduled for launch in Spring of 2005. Targeted at the architectural market, each issue will--like Inventables--include physical materials samples, printed design information, and on-line access to additional data.

Transstudio, by Blaine Brownell and NBBJ Architects, is also targeted at the architectural design industry and aims to provide information on materials most on the cutting-edge. Transtudio provides a product-of-the-week email newsletter, information on-line, and downloadable materials information in PDF format.

This author especially enjoy's Brownell's materials classification system, consisting of such categories as "Ultraperforming", "Repurposed", "Transformational" materials and others.

This article also illustrates some examples of new/innovative materials and their application in building design, and discusses some of the challenges designers face verifying performance and capabilities when specifying unconventional materials for their projects.

At the time of this writing, Materials ConneXion, DesignAid, and Materials Monthly are fee-based subscription services, whereas Transtudio’s information is available free of charge.

Florida Wind Codes Receive Scrutiny

New Florida Codes Bring Mixed Success, ENR August 23, 2004, reports on the aftermath of Hurricane Charley's passage over central Florida on Friday, August 13. Of particular interest are performance differences, if any, to be found between structures built before and after the mid-1990s, when substantial changes were made to Florida's building code wind design provisions in the aftermath of 1992's Hurricane Andrew.

The Turner Agri-Civic Center, designed to withstand 140-mph winds, collapsed in winds estimated at 100 to 110 mph.

Noteworthy points include:

• Wind speeds of up to 145 mph were recorded during Hurricane Charley.
• Mobile homes, designed to withstand 110-mph winds suffered significant damage.
• Charlotte County's three hospitals, all built before mid-1990 code revisions sustained damage. One hospital had to relocate 50 patients.
• Of perhaps even greater concern was the collapse of the Turner Agri-Civic Center in Arcadia. This two-year-old building was built to serve as a storm shelter and was designed to withstand 140-mph winds. However it collapsed under winds estimated at 100 to 110 mph. Over a thousand people in the shelter at the time safely evacuated prior to the collapse.
• In Punta County, every school except one suffered extensive damage. The exception, Sallie Jones Elementary School, was a two-story, tilt-up concrete structure with metal roof, and steel floor and roof framing. The school was designed to meet 2001 standards, including a 120-mph wind load. With an additional importance factor of 1.15, the effective design wind load was 138 mph.

Florida Changes Building Codes Between Storms, ENR September 9, 2004, reports on the Florida Building Commission's adoption of the International Building Code and a last minute amendment change to prevent a "loophole" in the new code that would relax wind design standards for a significant portion of the state.

According to the article, the International Code permits conventional construction in geographic areas with design wind speeds of 110 mph or less, whereas the existing Florida building code permits such conventional methods only in areas with design wind speeds below 100 mph. [Author's note, see International Residential Code R301.2.1.1 Design Criteria]. If left unchanged, the new code would have permitted approximately a quarter of the state to revert to conventional construction techniques not permitted for the last 10 years. As modified, conventional construction (e.g., no hurricane straps, no masonry reinforcing) is permitted in areas with design wind speeds less than 100 mph.

This article also makes some interesting observations regarding the effects of Hurricane Charley. For example, the hurricane destroyed approximately 10,000 homes and damaged another 16,000. But according to this article, all but a few of the destroyed homes were built to pre-2000 design standards.

MasterFormat 2004 Released

The Construction Specifications Institute (CSI) has released the final version of its updated MasterFormat system for organizing construction specifications. Dubbed MasterFormat 2004, this significant revision provides new divisions dedicated to disciplines previously under-represented, expands the numbering system to allow for greater depth of content, and also attempts to minimize disruption of the system's core architectural divisions.

The number of Divisions, the largest organizational groupings in the system, increases from 16 to 49. Major changes include:

• Division 02 Existing Conditions
• Divisions 20 - 29 Plumbing, HVAC, Electrical, Fire Suppression and other "Facilities Services"
• Divisions 20 - 39 Sitework, Transportation, Utilities, and other "Site and Infrastructure"
• Division 40 - 49 industrial "Process Equipment"

The numbering system itself has been expanded from five digits to six to create more space for individual Section numbers. For example, Clay Unit Masonry, previously Section 04210, is now Section 042100. Section numbers themselves are organized into two-digit groups, each group representing a finer level of subdivision. So in the previous example, '04' is referred to as the Division or "level one" designation, the middle '21’ is the level two designation, and the final '00' is level three. Level four designations can also be provided as two-digit suffixes. An example of how these level designations are used to subdivide specification content looks like this:

• Section 042000 Unit Masonry
• Section 042100 Clay Unit Masonry
• Section 042113 Brick Masonry
• Section 042113.13 Brick Veneer Masonry

Thankfully for architectural specifiers, Divisions 03 Concrete through 14 Conveying Equipment have undergone only modest updates, aside from the expanded numbering system itself.

More Information
_More information on the MasterFormat 2004 system is available on CSI's All About MasterFormat 2004 Edition page. A copy of the complete new system can also be downloaded from this page.
_The MasterFormat system and its role in the construction industry is discussed on pages 11 - 12 of the textbook. Section numbers relevant to specific content are also provided close to the end of each chapter.

Interim WTC Investigation Findings

The National Institute of Standards and Technology (NIST) has issued its second major progress report and interim findings related to the WTC disaster of 9/11/2001. The report discusses, in part:

• Working hypotheses for the collapses of the towers, as well as for the 47-story WTC 7 building.
• Factors contributing to the building collapses including the impacting aircraft, building structural systems, fireproofing, active fire protection systems, structural materials, and failure mechanisms.
• Emergency response, command and control, and communications during the disaster
• Applicable building codes at the time of the buildings' construction
• Design practices related to fire- and structural-safety, performance-based fire safety design, and the roles of building standards, codes, and regulations in such design
• Issues meriting further consideration

A few of the more interesting findings in the report include the following:

NIST's working hypothesis is that the towers failed due to column instability caused by the airplane impacts and subsequent fires. One question concerns why WTC 1 stood for nearly twice as long after plane impact as WTC 2. Though the report draws no inference, it notes separately that affected floors in WTC 1 had significantly upgraded amounts of fireproofing in comparison to affected floors in WTC 2.

The role of spray-on fireproofing in protecting the building frames from the heat of fire continues to receive considerable attention. Fireproofing thicknesses applied to the long-span floor trusses ranged from 1/2-inch to 1 1/2-inches. Separately, an unrelated 2001 model code report recommended 2-inch thickness for a similar floor system. These large discrepancies indicate a lack of technical basis for the fireproofing thicknesses used in the towers.

More than 99 percent of the tower occupants below the impact floors were able to evacuate safely prior to building collapse. Significant drops in evacuation rates prior to the collapses suggest that there was sufficient egress capacity to accommodate these building occupants. However, on the day of the attacks, both buildings were each occupied at approximately only 1/3 of full capacity. Estimates indicate that evacuation of either tower at full capacity would have required significantly more time, approximately 4 hours.

The towers were not constructed to meet requirements of the building code in effect at the time that they were built, the 1938 New York City Building Code. Rather, the Port Authority opted to conform to requirements of the upcoming 1968 Code, even though this new code was three years away from going into effect. As a result, significant reductions in life-safety requirements were applied, such as reduction in number of required stairwells, reduction in levels of fire-resistance ratings, and reduction in partition structural load requirements.

The Institute's Key Findings document is especially recommended for further reading.

More Info
NIST News Release
NIST Progress Report
Columns Likely Failed First in Terrorist-Triggered WTC Fires, ENR, June 28, 2004

Defensive Design Guidelines

DHS Announces New Building Safety Guidelines, Building Safety Bulletin, May 2004, describes new publications developed by the Federal Emergency Management Agency (FEMA) and released by the Department of Homeland Security related to the design and construction of buildings for resistance to terrorist attack. Documents available on FEMA's web site include:

• FEMA 426 - Reference Manual to Mitigate Potential Terrorist Attacks Against Buildings
• FEMA 427 - Primer for Design of Commercial Buildings to Mitigate Terrorist Attacks
• FEMA 428 - Primer for Design Safe School Projects in Case of Terrorist Attacks
• FEMA 429 - Insurance, Finance, and Regulation Primer for Terrorism Risk Management in Buildings
• E155 - Building Design for Homeland Security

Elevators and Emergency Egress

Industry group proposes use of elevators during fires, Building Design & Construction, 05-04, reports on plans by the elevator industry and standards organizations to develop elevator systems suitable for occupant egress and firefighter access during building emergencies.

According to the article, benefits of such "protected" elevator systems include reduction in building evacuation times by as much as 50%, and delivery of firefighters to upper floors in high-rises up to six times faster than possible by use of stairs. These plans took a significant step forward with a March workshop sponsored by the National Institute of Standards and Technology, attended by various stakeholders including the American Society of Mechanical Engineers, International Code Council, National Fire Protection Agency, Americans with Disabilities Act board members, elevator manufacturers, and industry consultants and experts.

According to the article, in twelve countries outside the US, lifts dedicated solely to firefighter access are required in buildings 30 meters or taller. In contrast, the plans being developed here in the US will rely on normal service elevators, and will provide not only firefighter access but also occupant evacuation capabilities. The basic operational strategy works as follows:

• When any detector in the building signals a fire alarm, one designated elevator is recalled to the ground floor and taken out of service, where it can be put back into service under manual control by emergency personnel.
• As long as smoke or heat detectors in elevator lobbies and hoistways do not signal alarms, other elevators would continue to operate normally.
• If lobby or hoistway detectors do signal, then all affected elevators would be similarly recalled.
• Advanced sensing and communications systems would allow emergency personnel to gauge occupant loads and fire conditions on individual floors. Using this information, occupants could be directed to wait for elevators at their current location, proceed to elevator lobbies on other floors, or exit the building by stairway.
• Elevators themselves would be protected from smoke and fire by 1-hour rated, pressurized lobbies and pressurized hoistways.
• Proposals for integrating elevator control and communications with HVAC and fire protection systems are also part of the planning.

More Information:
Conference Proceedings: Workshop On Use of Elevators In Fires And Other Emergenices

New Accessibility Guidelines Coming

New ADA and ABA Guidelines Approved, Building Safety Journal, March-April 2004, reports on the US Architectural and Transportation Barriers Compliance Board's January approval of new technical guidelines for complying with the requirements of the Americans With Disabilities Act (ADA). According to the article, the new guidelines will replace the current ADA Accessibility Guidelines (ADAAG) as well as the guidelines for accessibility under the requirements of the Architectural Barriers Act (ABA). The result will be a more consistant and detailed set of provisions for both sets of regulations, as well as closer coordination with some of the accessibility requirements of the International Building Code.

The new guidelines next proceed to the Office of Management and Budget for review, approval, and publication as Federal regulations. After publication, the various Federal Agencies that enforce ADA and ABA requirements, such as the Department of Justice, the Department of Transportation, and others must update their own standards for the new guidelines to come into effect.

Recap
The ADA Accessibility Guidelines cover the construction and alteration of private sector places of public accommodation and commercial facilities, and state and local government public sector facilities (but not Federal facilities). The accessibility guidelines issued under the ABA primarily address facilities built or funded in the Federal sector.

More Information:
Iano's Backfill Finding Your Way Through Accessibility Regulations
Federal Access Board ADA and ABA Accessibility Guidelines Homepage

Simpler Energy Codes Coming?

DOE Aims for Simpler Energy Code, Journal of Light Construction, March 2004, discusses efforts by the US Department of Energy to encourage simplification of the International Code Council's International Energy Code. According to the article, the proposed changes are intended to be "result-neutral", in that they will not increase or decrease baseline energy use requirements from the current version of the Energy code. But they will "drastically simplify" the code's prescriptive and performance based requirements. The article paraphrases DOE sentiments as "A strict energy code accomplishes little if it's too complicated to understand or enforce."

Some of the proposed changes include:

• Reduction in the number of US climate zones
• Simplification of climate zone boundaries by running boundaries along state lines where possible
• Elimination of window area restrictions
• Elimination of window-to-wall restrictions
• Allowance for building element tradeoffs that meet or exceed prescriptive requirements

The deadline for final public comments is April 2004.

More Information
DOE: Building Energy Codes - 2004 DOE ICC Code Proposals

Height & Area Requirements In The IBC

As noted in the textbook, the three previous US model code organizations have consolidated themselves into the International Code Council, and merged their model codes into the International Building Code. Recently, this author had reason to compare height and area limitations between one of the "legacy" model codes and the new International Building Code. It's no secret that the new code is at times less restrictive than its predecessors, but even knowing this in advance, the results were eye opening.

The following two charts are adapted from our design handbook, The Architect's Studio Companion. One portion of this book deals with the effects of the building code on building form by providing a series of charts that allow the designer to quickly determine allowable height and area for a project under consideration depending on such factors as applicable code, construction type, and related considerations. By comparing tables from an earlier edition of the Companion, that compiled results for the previous codes, with information from the latest edition, which refers to the new International Building Code, easy comparisons can be made.

Combustible Construction, UBC vs IBC
This first chart compares height and area limits for two codes, the "legacy" Uniform Building Code (UBC) and the International Building Code (IBC), for buildings with Occupancy Group B (Business) and constructed of combustible construction. The base chart (rendered in grey scale) represents data for the UBC. Information overlaid in blue represents data from the IBC.

Read the chart as follows:

• Various construction types and their level of fire protection are listed across the top rows of the chart. For example, "Wood light frame, 1-Hour" refers to stick built construction with 1-hour fire protection applied to the framing (typically in the form of fire-rated gypsum wallboard). Mill construction refers to buildings with noncombustible exterior wall construction and heavy timber framing for the interior structure. Noncombustible structures made from concrete or steel (included in the chart below) are listed simply according to the level of fire protection applied.
• Below the construction types, columns are further divided to distinguish between sprinklered ("Spr") and unsprinklered ("Unspr") buildings.
• Once a construction type, level of fire protection, and sprinkler condition have been established, allowable height and area can be read as follows. For maximum height in feet, read from the row directly below the sprinkler designation row. ("UH" on the chart below refers to unlimited height.)
• For maximum height in stories, proceed down a column until arriving at the solid horizontal line. Read across to the side of the chart to find the allowable stories permitted.
• To determine the maximum permitted area for the building, read the number directly below (or above, where space was limited) the solid line. This is the maximum allowable area for all floors of the building. ("UA" refers to unlimited area.)

Keeping in mind that data for the IBC is rendered in blue, a few facts are readily apparent:

1. For the cases illustrated here, more often than not, the IBC is moderately more generous in its allowable building height than the UBC.
2. In these cases the IBC is significantly more generous in its allowable building area than the UBC. This is particularly true for sprinklered buildings, where on average, the allowable area for all floors has increased by a factor of 7 times in comparison to allowable area for the UBC.

Noncombustible Construction, UBC vs IBC
This second example continues the comparison for noncombustible construction types, for the same Occupancy Group B.

The results are similar: The IBC is more often than notgenerous in allowable height than the UBC. But the IBC is significantly more generous in its allowable area than the UBC, particularly for cases where the building is sprinklered. (Though not illustrated here, the same trends are true for most other occupancy groups as well.)

Comments
Reportedly, at the time of the creation of the IBC, the approach taken to establishing height and area limitations was to take the least restrictive requirements from any of the three legacy codes and apply those requirements to the new code. As it was explained to this author by one representative of the International Code Council, this decision was based on the absence of any data indicating any one of the legacy code's limits was technically superior to the others.

For any design and construction professional interested in the topic of building safety, these are interesting times. A confluence of events have brought new attention to a number of questions that have always been part of this profession, but that often may be taken for granted by many of us. To name just a few: How is building safety measured? Who decides what constitutes a reasonably safe building? Who should be responsible for ensuring the safety of buildings? This site will continue to report on developments in these areas as they arise.

More Information
Category 01 Making Buildings on this site includes articles related to regulation of construction, building codes, and the general considerations of how buildings get built. Category wtc on this site includes articles related to building safety and in particular issues arising out of the collapse of the World Trade Center towers. Many of the articles in both of the categories link to other Web resources for further coverage of these topics.

For an introduction to building codes, Occupancy Groups, Construction Types, Height and Area restrictions, and related topics, see pages 4 - 10 of the textbook.

Finding Your Way Through Accessibility Regulations

15 Minutes with the ICC Staff, Building Safety Journal, January-February 2004, provides a summary of many of the accessibility regulations and standards that may apply to building design. As a first step to navigating the maze of regulations and their acronyms, it is useful to recognize that broadly speaking, requirements break down into two categories: The regulations that establish a requirement to provide accessibility, and the standards a regulation points to for compliance. For example, according to the article:

• The International Building Code (IBC), Chapter 11, references ICC/ANSI A117.1, Accessible and Usable Buildings and Facilities.
• The Americans with Disabilities Act (ADA) references both the Americans with Disabilities Act Accessibility Guidelines (ADAAG) and Uniform Federal Accessibility Standards (UFAS).
• The Fair Housing Amendments Act (FHA) references the Fair Housing Accessibility Guidelines (FHAG).

It is important to know when which standards apply, and how they are enforced. For example: ICC/ANSI A117.1 applies wherever the International Building Code is in effect. It is enforced by the building department having jurisdiction. The ADA standards, ADAAG and UFAS, apply mostly to non-residential buildings, and the FHA's FHAG standards apply to housing. Enforcement of ADA and FHA requirements is through the Federal judicial system, not through building departments.

It is also helpful to know where standards originate from. The International Building Code comes from the International Code Council, an organization originating from the consolidation of the three legacy model code organizations in the US. The ADA and its standards come from the Architectural and Transportation Barriers Compliance Board. The US Department of Housing and Urban Development (HUD) is responsible for the FHAG standards. Confused yet?

Finally, in some cases, compliance with one standard can be relied on to ensure compliance with another. For example, compliance with ICC/ANSI A117.1 in the International Building Code is sufficient to ensure compliance with HUD's FHAG requirements. The International Code Council is also working to make its standards sufficient to ensure compliance with ADA requirements, though this is not the case at this time.

(Author's note: The article fails to mention other possible sources of accessibility requirements including for example Section 504 of the Rehabilitation Act of 1973, the federal Architectural Barriers Act, and state or local accessibility requirements.)

More Information
The US Access Board Home Page is a good starting point for researching Federal accessibility laws.
The Access Board's About Page provides links to all key Federal accessibility laws.
The Access Board's FAQ Page is a good place to find answers to common questions regarding accessibility laws.
The ADA Home Page provide links to information specific to the Americans With Disabilities Act.
The US Department of Justice's A Guide to Disability Rights Laws provides 23 pages of reference information related to Federal accessibility laws.

Standards
ADA Standards for Accessible Design
Uniform Federal Accessibility Standards
Fair Housing Accessibility Guidelines
ICC/ANSI A117.1 can be order from the International Code Council's online store.

More On Highrise Safety

The debate on building safety continues...

Building Safety Journal
Fire Protection - The Fire Service Viewpoint?, Building Safety Journal, January-February 2004, (available online at the time of this writing) rebuts charges that current building standards allow construction of buildings that are unsafe for firefighters during building fires. This article, authored by fire protection engineer Richard C. Schulte, is perhaps most noteworthy for the prominence granted to it by its publication in the International Code Council's flagship journal. This author found the arguments put forth in the article less than compelling.

Metropolis Magazine
Shortcuts to Safety, Metropolis Magazine, March 2004, takes the position that "Two and a half years after the worst tragedy in skyscraper history, highrises are no safer." This is an informative article offering insights this author has not encountered elsewhere on this topic. Whether or not one agrees with its premise, this article is worth the attention of those concerned with the topic.

Some of the key points raised in this article include:

• The Skyscraper Safety Campaign, founded by the family of a firefighter lost in the disaster, has played a prominent role in raising issues of building safety and pushing for investigation into the causes of the building collapses. According to the article, this group was partially responsible for the creation of the ongoing investigation by the National Institute of Standards and Technology.
• Though building safety standards are enforced through public regulation, the standards themselves are crafted in the private sector, and to a significant extent by the same parties with an interest in minimizing building costs. As an example, the article cites New York City's own building regulation department, the Department of Building, that has a dual mission of maintaining building safety while also "streamlining the occupancy of new and existing office space".
• According to sources quoted in the article, the standards of safety applied to the World Trade Center towers were sufficiently lax that these buildings could not have been built in Germany, the United Kingdom, Japan, or even possibly in any American city--including New York City--if they had had to meet local building code requirements. (The developer of the towers, the Port Authority of New York is exempt from City building and fire department regulation.)
• Trends in construction since World War II toward lighter construction materials and assemblies have resulted in building systems that some argue are less resistant to fire and that are less safe for building occupants and fire fighters.

The article also discusses the reconstruction of Seven WTC, the 47-story highrise that collapsed due to fire some hours after the two main towers. The new building, dubbed "Seven II", is being built to standards significantly in excess of current code requirements including a reinforced concrete core, fire sprinklers with double the required supply capacity, exit stairs 20 percent wider than required, and other safety features. The article also notes that these enhancements may reflect both the developer's good intentions and/or economic realities of insuring a building in this sensitive location.

For more on this topic, see the previous articles on this site:
Fire-Safe Debate
The Current State of Fire Protection Design
Debate Over Fire Testing

Integrated Steel Design

To Help Save Time, Structural Engineer Wears Harder Hat, ENR, February 2, 2004, describes Tacoma Washington's use of innovative CAD modeling and fabrication techniques to preorder structural steel for the 279,000 square foot Mt. Tahoma High School. On this project, engineers Putnam Collins Scott Associates developed a digital three-dimensional object based model from which steel detailing and fabrication could proceed. This process effectively removed steel procurement and detailing from the project's critical path and shaved close to three months off of the project's construction schedule.

The ENR article discusses both the risks and potential benefits of these so-called integrated steel design (ISD) techniques. On the Mt. Tahoma High School project, they were highly successful. In addition to reductions in the construction schedule, the engineers claim that there were only 13 RFIs related to structural steel (an unusually low number for a project of this size); of over 2900 anchor bolts only four for one base plate required modification; and of over 15,000 bolted connections, there were no mismatches.

These techniques also create new risks. With ISD, the owner's design team takes responsibility for steel detailing, instead of the general contractor and its suppliers. Additionally, with ISD, steel detailing information flows directly from the design model to the fabricator, without separate review by the general contractor or steel fabricator. This requires a steel designer sufficiently knowledgeable regarding steel fabrication and erection.

Fire-Safe Debate

With the World Trade Center collapses, several recent catastrophic building fires, and the publication of two new model building codes, fire safety in buildings is getting more than its usual share of attention. Two recent opinion articles take the position that current trends toward relaxing building fire safety requirements are ill advised and should be reconsidered.

Reliance on sprinklers a mistake, Building Design & Construction, 01.04, takes the position that "building codes...are based on the mistaken assumption that sprinklers virtually never fail and that fire-resistant construction materials can, therefore, be minimized or eliminated". This guest commentary piece is authored by W. Gene Corley, PhD, Senior VP, Construction Technology Laboratories, and team leader for FEMA's WTC Building Performance Study.

Some of Sorley's assertions include:

• Sprinkler failure rates may be as high as 16%.
• The trend in the model codes is toward increasing reliance on sprinklers, while reducing requirements for fireproofing, fire-barriers, and smoke-barriers.
• Fire-barriers and smoke-barriers are considered "life savers" by fire fighting personnel, and they reduce the risk of building collapse.

Sorley continues with examples gleaned from his his experience as a lead investigator of the WTC disaster. He then offers more criticism for the International Building Code (IBC), which he claims has "drastically lowered" requirements for fire-resistant construction in comparison to older model codes. Sorely concludes with the advice that building fire safety requires both sprinkers and fire-resistant construction to best ensure the safety of building occupants and emergency responders.

Fire-Safe Buildings and Masonry Codes, Masonry Today, Winter 2003/2004, takes a similar position, stating "Today's building code officials should be encouraged to develop code provisions that provide an improved level of redundancy for life safety, property proteciton, and welfare of the general public". This article is written by Stephen Szoke, Director of Codes and Standards, Portland Cement Association.

Szoke states that in the process of merging the three previous model building codes, the least restrictive passive fire protection requirements from these codes were used as the basis for the requirements in the new IBC. Furthermore, new code change proposals seek to reduce even further the IBC's passive fire protection requirements.

Szoke goes on to make a number of arguments for reconsidering an overreliance on fire sprinklers in buidings, including considerations of:

• Aging population
• Risk of malicious disabling of fire sprinkler systems
• Trends in other aspects of the building code toward more stringent safety requirements
• Increased construction of multi-family building types
• Sprinkler system effectiveness
• Sprinkler malfunctions
• Reliable water supply for sprinklers

Szoke advocates a "balanced design" approach to fire-safe construction that relies on both sprinkler systems and the redundancy of passive fire-resistant construction. He further recommends building designers consider in some circumstances exceeding current code fire-separation requirements.

This Author's Comments
Readers should take note that both authors cited above are associated with construction trade groups that have an ecomonic interest in promoting non-combustible construction methods. Construction Technology Laboratories, of which Sorley is a Senior Vice President, is closely associated with the American Institute for Concrete Construction. Szoke's organization, PCA, is a promoter of concrete and masonry materials and construction. (Szoke is quite forthright in his article concerning his association and interests in this matter. He states "PCA and allied industry groups advocate changes to increase passive fire protection for buildings...")

Despite these authors' perhaps vested interests, it is this author's opinion that their points are well founded and worthy of serious consideration.

Construction Innovation, December 2003

Canada's Institute for Research In Construction December 2003 Newsletter Construction Innovation includes the following items that may be of interest to users of Fundamentals of Building Construction:

• Fire researchers develop new tool for assessing fire resistance of wall assemblies using numerical modelling describes numerical modeling techniques being applied to the prediction of structural failure of residential building assemblies exposed to fire. This model is being verified experimentally, and when completed will allow assessment of the fire-resistance of assemblies for less cost than required by traditional testing techniques. For example, the buckling of a wood stud assembly under structural loads, due to fire's effects of heat, advance of char layer, and gradual joint openings can be predicted for untested assemblies.
• Realistic fire simulations will be used in fire-safety analysis and design describes the development of improved fire load modeling for use in the prediction of fire effects. Data developed from these simulations will allow the more realistic modeling of fire characteristics such as release of heat energy, size of fire, rate of spread, yield of products of combustion, and hot gas temperatures.
• Results of IRC's material properties studies now available describes IRC's database of over 100 building materials and their properites of heat capacity, thermal conductivity, water vapor permeance, equilibrium moisture content, liquid water diffusivity, and air permeance. The influence of relative humidity, water concentration, and air pressure differentials on these properites are also considered.
• IRC will host world building congress in Toronto details the upcoming CIB World Building Congress 2004, scheduled for May 2 to 7. This event is expected to draw approximately 700 participants from 40 countries and covers various aspects of building technology and construction, such as the construction process, trends in codes and regulatory systems, security in tall buildings, fire and structural safety, indoor air quality, energy conservation, and more.

Wildfire Code Guidelines

Urban-Wildfire Interface Code Offered Free to Communities to Defend Against Wildfire, Building Safety Bulletin (Newsletter of the ICC), January 2004, reports on the International Code Council providing its Wildfire code free to communities building in wildfire prone areas. This brief article also provides a summary of recommendations for homeowners, some examples which related to building construction include:

• Build with fire-retardant roof materials
• Use fire-resistant materials for siding and exterior walls
• Use tempered single-glazing, or use double- or triple-glazing in exterior windows, to reduce heat radiation into the interior, and to protect against glass breakage
• Consider residential fire sprinkler systems to extinguish fire that does enter a home, or to prevent an inside house fire from spreading to the out of doors.

More Information:
Federal Emergency Management Agency's How-To Series: Protecting Your Property From Wildfires
The UC Berkely Forest Products Lab Fire Mitigation page provides links to publications, information about testing, and more resources related to wildfire mitigation.
The International Code Council's Wildfire Safety page provides tips to homeowners on protecting the home and property from the threat of wildfires.

Ongoing NIST Research Into 9/11

Reliving 9/11, With Fire as Teacher, New York Times January 6, 2004, describes ongoing research by the National Institute of Standards and Technology into the causes of the collapse of the World Trade Center towers. Aspects of the NIST efforts discussed in this article include:

• Full-scale mockups and fire-testing of office workstation clusters to better understand the intensity and behavior of the fires that eventually weakened the building structure and lead to the collapse of the towers
• Testing of steel samples from salvaged structure to determine its strength characteristics under very rapid loading as was experienced during the planes' impacts
• Development of a detailed model of how heat from the fire seeped into structural elements and affected the structures' strength and stability
• Impact resistance testing of fireproofing insulation to determine the extent to which it may have been dislodged from structural elements during the intial impacts, thereby leaving the steel more vulnerable to the subsequent building fire

According to the article, NIST's findings could lead to new safety recommendations for ordinary high-rise construction. It is also expected to significantly advance the science of fire and how it affects structure.

Reverse Auctioning of Construction Services

AGC cautions on use of 'reverse auctioning', Building Design & Construction, 12.03, reports on the Association of General Contractors of America's recent report to members urging caution when considering the purchasing or bidding of construction services through recently devised "reverse auction" procurement systems.

Reverse auction systems are typically hosted through Internet enabled e-commerce hosts. More frequently applied to the procurement of commodities and manufactured goods, these systems are now finding their way into the construction services realm. In such a system, bids are submitted electronically. Submitted bid amounts are visible to all bidders. As lower bids from competing providers are received, other bidders are encouraged to revise and resubmit their own, lower bids. In some cases bid revision cycles may occur in just a matter of minutes. Purported benefits include increased price competition, increased size of bidder group, and reduced time required for receipt of bids.

The major concerns raised by AGC include:

• Reverse auctions do not guarantee lowest price.
• Reverse auctions may encourage imprudent bidding.
• Negotiated procurement allows more thorough evaulation of bid value.
• Sealed bidding ensures that the successful bidder is responsive and responsibile.
• Reverse auctions may contravene federal procurement laws and certain state laws.

At the time of this writing, AGC's full report is available on line at White Paper on Reverse Auctions. This white paper also takes a strong position regarding the distinctions between traditional manufacturing and building construction:

[Reverse auctioning] ignores the unique nature of construction. Construction contractors, specialty contractors, subcontractors and suppliers offer and provide a mix of services, materials and systems. They do not “manufacture” buildings, highways, or other facilities. In fact, the construction process is fundamentally different from the manufacturing process.

To this author, the AGC's statements look like more than just a position against reverse auctioning, but also a broader charge against the increasing interest in applying manufacturing principles to construction industry services. See Category project design/project delivery innovations (on this site) for additional future articles on this topic.

WTC Investigation Progress

Trade Center Probe Clears Data Hurdles, ENR December 15, 2003, reports on progress in the federal investigation into the World Trade Center disaster. According to the article, the US Commerce Department's National Institute of Standards and Technology (NIST) has released an interim progress report stating in part, that investigators now have access to all the information needed for their research.

According to the article, NIST's examples of ongoing work include:

• Modeling of collapse scenarios
• Analysis of structural steel recovered from the collapse site
• Fire tests of office workstation mockups
• Fire endurance testing of typical tower floor systems
• Analysis of active fire protection systems (e.g., sprinklers) in use in the two main towers as well as the 50 story 7 WTC building that also collapsed due to fire
• Analysis of as-built fireproofing conditions and the impact of missing or under-applied fireproofing
• Analysis of airplane impacts on the structures

The article also reports on some controversy within the design community regarding the value of a detailed, comprehensive, and costly investigation of the tower collapses. Some see value in learning as much as possible about these events. On the other hand, Jon D. Magnusson, CEO of Magnusson Klemenic Associates is quoted as saying "The reality is that it doesn't matter if the floor trusses, the columns, or the connections went first [because] we can't out-build the terrorists." Magnusson also argues that details of the fireproofing performance may be irrelevant, since fireproofing of any type would have failed under similar conditions of airplane impact.

Separately, in Trade Center Fireproofing Tests Suggest a Wider Safety Problem, the New York Times (December 14, 2003) reports that preliminary calculations by federal investigators indicate that even relatively small gaps in spray applied fireproofing may leave a steel structure more vulnerable to the heat of fire than previously thought. According to the article, heat from a fire can enter into the structural steel at locations of missing fireproofing, and then become trapped and build up in adjacent insulated portions of the steel members. While noting that information being developed is still preliminary in nature, the article goes on to raise questions regarding the safety of fireproofing in other existing buildings. For example, the article quotes Glenn P. Corbett, a member of the investigation's advisory committee and an assistant professor of fire science at the John Jay College of Criminal Justice as saying, "When the investigation is over, this issue will radiate out to other buildings that have fireproofing in them. We really have to decide whether it's appropriate to continue to use this type of material."

NIST'S WTC investigation web site provides more information on this investigation. According to this site, the investigation has three main parts:

1. A 24-month building and fire safety investigation to determine probable causes of the collapses
2. A research and development program to provide the basis for improved codes and standards
3. A program for dissemating information and assisting the building industry in implementing recommended changes in practice

This site provides additional information including interim reports, background information, photos and simulations, and more.

AR Annual Product Reports

Architecture Record's annual Product Reports is a diverse listing of what this magazine's editors consider to be the latest, most innovative offerings from the building manufacturing industry. Categories include Editors Picks, Top 10 Green Products, Digital Products, and various materials and systems roughly following the CSI MasterFormat division organization.

Prefab Modern

Prefabrication, the Speculative Builder’s Tool, Has Been Discovered by Modernist Designers, Architecture Record 12.03, is a continuing education article that discusses recent developments in architects' application of prefabrication technologies to the residential home market. This in an interesting, wide-ranging article from both design and technology standpoints.

The work of featured architects is particularly worth a look:

• Resolution: 4 Architecture's winning entry in Dwell magazine's competition for prefabricated homes is based on traditional modular construction. This project is not only conceptual--it will soon be built for a North Carolina client.
• Nottoscale
have developed a modular system based on automotive manufacturing principals.
• Designer Tim Pyne's m-house is based on traditional mobile home technology.
• Architects KieranTimberlake Associates used off-site fabrication techniques to overcome challanging site and scheduling issues for Upper Court, Pierson College, a new dormitory addition at Yale University.

Another interesting resource identified in this article is Michael Sylvester's fabprefab site dedicated to prefabricated and modular systems for construction of homes in the modernist style.

Indictments in Rhode Island Nightclub Fire

3 Men Are Indicted in Fire at Rhode Island Nightclub, New York Times December 10, 2003, reports that two owners of the Rhode Island night club and a rock band tour manager have been indicted on involuntary manslaughter charges for their parts in the February 2003 fire that killed 100 and injured nearly 200 more. The purported causes of the fire are pyrotechnics ignited by the band during their performance and the presence of a highly flammable polyurethane acoustical foam insulation that had been installed by the owners.

What controls on the design and building process exist to prevent such disasters?

The Building Code
Combustibility of interior finishes is regulated by the building code. For example, in the International Building Code, Chapter 8 provides requirements for interior finishes, including their combustibility. As an example of these requirements, see Figure 22.5, page 797 in the text, which illustrates Table 803.4 from the IBC. However, in the specific case of foam plastic, an earlier paragraph in this chapter of the code states that foam plastics may not be used as an interior finish at all, except as specifically provided for in a separate chapter devoted entirely to plastics, Chapter 26.

Fire-resistance rated construction is also addressed in Chapter 7 of the IBC, and thermal and acoustical insulation materials are specifically addressed in Section 719. However this section also indicates that in the case of foam plastic insulation, the requirements of Chapter 26 apply.

Chapter 26 Plastics of the IBC does provide detailed requirements for the use of foam plastic insulation in buildings. Here are some of the more relevant points:

• Packaging of foam plastic materials brought to the project site must provide information about the product, the product manufacturer, and how the material is permitted to be used in building construction. The labeling itself must be produced by a testing and labeling agency recognized and approved by the building department.
• Combustibility limits are set for foam plastic insulation. Generally restrictions are comparable to a Class B interior finish material.
• Under most circumstances, foam plastics cannot remain exposed in finished construction. They must be covered by a 1/2 inch layer of gypsum wallboard or some other thermal barrier material that can provide protection from the heat of a building fire.
• Foam plastics may be used as an exposed finish, without the normally required thermal barrier, when specially tested and demonstrated to not present a special fire hazard under these conditions.
• A variety of additional special circumstances, too numerous and complex to discuss here, are described where it may be permissible to use exposed foam plastics in the building without the normally required thermal barrier protection.

So in the case of the Rhode Island night club, if regulated by the IBC, the installed materials would have to have been labeled for the intended use, and either covered by a protective thermal barrier material in the finished construction, or specifically tested and approved for use in an exposed finish application. (Other building codes contain roughly similar requirements.)

Other Sources of Regulation
Fire codes regulate the ongoing use and maintenance of buildings, and in some cases aspects of building design and construction as well. States and local municipalities may legislate regulations independently from building and fire code requirements. Organizations may adopt voluntary standards--see for example NFPA 1126, Use of Pyrotechnics before a Proximate Audience.

More Information:
Nighclub safety equals life safety, NFPA Journal July 8, 2003, provides a comprehensive discussion of the factors surrounding this event and related information.
Alliance for the Polyurethanes Industry, Polyurethane Combustibility in the Regulatory Environment

The Benefits of Schools Built for Sustainability

The Sustainable Buildings Industry Council is offering a free video series about "...how High-Performance School Buildings boost student health and productivity, conserve energy and water and other natural resources, and save communities money."

Major topics include:

• Overview of High-Performance School Buildings
• Building Blocks of a High-Performance School Building
• Benefits of a High-Performance School Building
• How do you Create a High-Performance School Building: Eight Steps for Managing the Process

This is a worthwhile resources for design professionals and educational facility clients alike.

What is Hypertrack Construction?

Hypertrack Projects Push Too Hard (ENR, December 1 2003) claims that fast-track project delivery is now the norm, that super-accelerated projects, aka "hypertrack", are becoming more common--and that the construction industry is suffering as a result. Yet this piece does not provide much of an explanation of what hypertrack construction is.

So what is "hypertrack"? A few hits from Google produced the following:

Conference Explores Informed Architecture (Architecture Week, February 14 2001) describes hypertrack as "instead of working sequentially — first programming then schematic design then design development then construction documents then construction administration — much of the work was done simultaneously".

GETTING UK CONSTRUCTION PEOPLE TO THINK LEAN - WHERE TO START? A CASE STUDY (Sixth Annual Conference of the International Group for Lean Construction) proposes:

• An "open and equal" culture
• A flattened structure of authority
• Trust and empowerment in decision-making
• Improved teamwork
• Improvement in the speed of decision making
• All participants on site
• Equality as partners
• Site based design
• Suppliers regarded as part of the team

Hypertrack (H+M Company, Inc.) in a more promotional vein boasts "Techniques such as just-in-time delivery and parallel workflow models have been implemented at H+M’s construction sites. 'We literally take the joists off of the truck, panelize them and set them in place. They never touch the ground...'"

Returning to Hypertrack Projects Push Too Hard, some of the risks cited for this method of project delivery include large change orders, serious schedule delays, inflexible scheduling, over reliance on top-level personnel, and handcuffed design. While admitting that hypertrack is appropriate for some project circumstances, the article encourages architects and construction managers to resist the increasing pressure to adopt hypertrack techniques as the construction industry's standard method of project delivery.

Steel Fire Protection Basics

Fire Protection of Structural Steel, Structural Engineer November 2003, is a comprehensive introduction to this subject, including discussion of building code requirements, the effects of high temperature on the physcial properties of structural steel, fire protection materials, and fire-resistant design methods. A few examples of what is included:

Types of fire protection materials and how they work are summarized:

• Low thermal conductivity (e.g., insulating materials, like spray fireproofing)
• High effective heat capacity (e.g., a relatively heavy steel member can absorb more heat with a lower rise in its temperature than a lighter steel member)
• Heat absorbing physical or chemical reactions (e.g., the heat-absorbing capacity of gypsum wallboard exposed to fire temperatures)
• Intumescence (e.g., intumescent paints that expand under exposure to fire temperatures, thereby creating an insulating layer)
• Radiation or reflection (metal or other reflective materials that reduce heat transfer by radiation)

The difference between restrained and unrestrained assemblies, the understanding of which is essential to applying fire system tests to actual project requirements, is explained.

A step-by-step example of calculating the required fire-protection thicknesses for a hypothetical steel framed floor assembly is included.

For students or professionals who need to understand how to apply fire protection concepts to actual projects, this article is useful resource.

More information:
For more on fire protection of structural steel, see pages 414 - 418 of the textbook.

White Paper On The Green Building Movement

Building Design & Construction Magazine has produced its White Paper on Sustainability, A Report on the Green Building Movement. This author highly recommends this thoughtful and comprehensive assessment of the state of the art to any serious student or practitioner of green building. Contents include the history of green building, LEED basics, survey results of BD&C's readership, developments in green building at the international, federal, state, and local levels, costs of green building, selecting green products, the future of green building and more.

Concluding Action Plan points include, in part:

• Conduct peer-reviewed studies of the benefits of green buildings related to human performance, health, and well-being.
• Enlist the real estate brokerage, financial, and appraisal community to champion a rigorous, peer-reviewed study of the economic and "business-case" aspects of sustainable design.
• Establish an Institute for Sustainable Development Research, pooling the resources of major universities, the Federal government, and the private sector.
• Launch a pilot program to measure the impact of green schools on student achievement and health.
• Reconsider the admission of trade associations to the GBC (up until now excluded from membership).
• Continue to upgrade LEED.

High-Rise Safety

Topics related to high-rise safety continue to receive substantial attention in the industry and the trade press.

Progressive Collapse, Building Design & Construction 11-03, starts off making the interesting point that the building industry does not even have an agreed upon definition of what constitutes "progressive collapse". Furthermore, in the case of the World Trace Centers disaster, the fact that both buildings withstood the initial impacts of the airliners despite massive structural damage makes it difficult to categorize the response of these structures in any simple terms.

Some other topics discussed in this article include:

• Since the exact nature of events of this type cannot be foreseen, a general approach to alternate load path design is recommended. In the event of the failure of a primary structural element, the structure should have the capacity to redirect loads to alternate elements in the structure, preventing further collapse.
• Design criteria for resisting progressive collapse scenarios are less restrictive than normal service loads. For example, deflections larger than can be tolerated under normal service conditions may be acceptable as long as safe egress routes are maintained.
• Blast resistant design has been a concern for certain types of overseas projects for as long as a quarter century. Research on blast resistant design increased after the 1995 bombing of the Murrah Federal Office Building in Oklahoma City. Especially since 9/11, security concerns for domestic structures have further increased.
• Design for increasing survivability of the structure depends first on the determination of possible hazards or threats. Examples of specific design strategies include hardening only the floors closest to the ground where a blast is most likely to occur, or embedding steel cables in the perimeter of the building floor slabs to allow load transfer in the event of the loss of a perimeter column.
• Both the ductility of structural steel and the continuity of cast-in-place concrete are beneficial to collapse-resistant design. Increasing load capacity, redundancy, and continuity all may contribute to greater suvivability.

This article also discusses design for fire resistance, and the use of advanced modeling techniques for more accurate prediction of egress effectiveness.

Defensive Design, Modern Steel Construction November 2003, provides a more in-depth and technical discussion of design for blast resistance and prevention of progressive collapse. Topics include:

• Performance versus prescriptive design


• Blast threat analysis
• Strategies for typical buildings: Even without special design effort, there are techniques for maximizing the survivability of a structure.
• Strategies for prescriptive building designs: As an example, a prescriptive requirement might be the capability of a structure to withstand the removal of a column. This requirement may be established without necessarily performing any project-specific analysis of risks and effects.
• Strategies for performance-based building designs: In high-risk situations, project specific threats and event effects are analyzed, survivability criteria are established, and design proceeds accordingly.

For architects and other non-structural designers, it is worth noting that performance-based design for building survivability may extend beyond structural considerations to affect wall assemblies, fenestration, site design, egress design, and other aspects of a project.

As another example of the current level of attention be given to these issues, the American Institute of Steel Construction is sponsoring a Blast and Progressive Collapse Symposium, December 4 - 5, McGraw-Hill Auditorium, New York City.

References:
Progressive Collapse Analysis and Design Guidelines for New Federal Office Buildings and Major Modernization Projects, General Services Administration.
DoD Minimum Antiterrorism Standards for Buildings, US Department of Defense.

Author's Footnote
While preparing this article, this author found it difficult not to ponder what might be the the broader, non-technical implications of living in a time when threats and risks become the driving forces in design. For readers wishing to pursue this question further, here are a few starting points:
Architecture Record's online open discussion Forums, including topic areas specific to the WTC events, tall buildings, etc.
The Security Paradox, Editorial, Architectural Record April 2002.
Being Pro-City, But Anti-Terrorism, Urban Journal, Metropolis Magazine.

The Code Authority Fall 2003

The 2003 Issue of Underwriter Laboratory's online newsletter for code community includes articles on:

Fire Resistance vs. Surface Burning Characteristics discusses the difference between fire-resitance ratings for walls and ceilings, and surface burning and smoke developed limits for finish materials. In a nutshell, partitions and ceilings are rated according to their capacity to contain the spread of fire. Finishes are rated according to their propensity to spread flame along the finished surface and generate combustion smoke.

Limited Combustible Cable Category Created discusses a newly created classification for telecommunications cabling used in air plenums, where the cable's surface burning and smoke developed characteristics are a concern. The new category surpasses the current minimum requirements (in NFPA 90A) and has been developed in response to the increasing density of cabling within such spaces.

Here Comes the Sun discusses photovotaic solar electric systems and related issues such as system types, connecting to the local power grid, integration of systems into traditional building components (e.g., PV modules as part of roofing shingles), and safety issues.

Leed CS Rating

Earlier this year, the US Green Building Council released its LEED Rating System for Core and Shell.

The purpose of this separate rating system is to open up LEED certification to projects where the building developer does not control buildout of tenant spaces, when such work is contracted separately at a later date.

Code Forums

The International Code Council's ICC Bulletin Board is a useful resource for professionals looking for building code guidance, and potentially a good learning tool for students.

Perhaps a worthwhile assignment would be to select several real-life questions from the forum, have students research the answers, and then compare their answers with those offered on the forum.

ICC also sponsors email lists, for those who prefer this format.

Chicago High-Rise Fire May Instigate New Sprinkler Requirements

Chicago Considers Requiring Sprinklers in Existing High-Rises, ENR November 24, 2003, reports that the Chicago city council is considering proposals to require retroactive installation of sprinklers in buildings taller than 80 stories built before 1975. Options include 5-year or 13-year phase in requirements, and possible exemptions for residential towers that either demonstrate undue financial hardship or pass a professionally certified life-safety evacuation evaluation.

The proposals are in reponse to an October 17 fire in Cook County’s 35-story administration building. Six office workers died of smoke inhalation while attempting to evacuate the building via one of the building's exit stairways.

New ASTM Journal

As of January 2004 ASTM International is set to launch a new online technical publication. According to ASTM's web site, the Journal of ASTM International will cover the full range of ASTM's technical interests, including among other areas Materials Performance and Characterization, Civil Engineering and Building Materials, and General Methods and Instrumentation. The journal will be published ten times per year on a subscription basis.

Building Safety & WTC

Building Standards, July-August 2002, devoted several feature articles to the topic of building safety after 9/11. Published by the former ICBO (now part of the ICC), these articles were still available online at the time of this writing at Building Standards Online.

Building Safety After 9/11: Where Do We Go From Here? discusses improving safety and security, the process for evaluation of code changes, and performance-based design goals.

Author's interpretation of building performance levels matrix illustrated in Building Safety After 9/11.

What Does September 11th Mean for Building Structure Design? discusses the prospect of making buildings more resistant to terrorist attack, the feasibility of designing buildings to withstand direcxt airplane hits, and minimizing the risk of progressive collapse.

Enhanced Emergency High-Rise Evacuation discusses current typical layouts for egress components and proposed improvements for enhanced life safety.

Additional related articles are entitled Protective Design: Saving Lives Through Structural Engineering, Educating the Public On Safety In Tall Buildings, and Engineering Systems and an Incremental Response to Terrorist Threat.