Iano's backfill

Sustainable Very Tall Buildings

Newton Suites and other endeavors (video, Council On Tall Buildings and Urban Habitat) is an interesting lecture given to the Council at their October 2009, Chicago conferance. WOHA founding partner Mun Summ Wong's disusses sustainable tall buildings. Some of the idea discussed include:

Monsoon windows Natural ventilation Daylighting Natural clothes drying Double-skin facades Sky streets Sky parks/sky gardens Intimate scales within a taller structure Vertical green Individualization of facades elements

The Comparitive Sustainability of Structural Materials

Materials Matter (Architecture Record, March 2011) compares the life cycle effects of wood, steel, and concrete construction. this article provides an informative discussion of life cycle analysis techniques and interesting comparisons of these three structural materials. (Caveat: The article is sponsored by a group affiliated with the forestry industry.)

Regarding comparing the embodied effects of various building materials, the current issue of Architecture Record (March 2011, p. 115) has an article comparing the life cycle effects of wood, steel, and concrete construction. As I mentioned in my talk, this article was sponsored by a group affiliated with the forestry industry. Nevertheless, I think the material is useful.

 

The article is also available online here: http://continuingeducation.construction.com/article.php?L=221&C=754 .

The Growth of Green Building

Is the rate of growth of green building high (The Extraordinary Growth of Green Building – A Rebuttal to The Green Building Adoption Rate is Slow, Find Out The Practical Reasons Why, greeneconomypost.com, February 18, 20011)?

Or is it low (The Green Building Adoption Rate is Slow, Find Out The Practical Reasons Why, greeneconomypost.com, January 6, 2011)?

Net-Zero Growth

Tallest Net-Zero-Energy-Use Building in U.S. Planned for Portland, Ore., enr.construction.com, 12/8/10, reports on the planned construction of the 7- to 9-story Oregon Sustainability Center. The project is being designed to receive Living Building Challenge certification, which includes in part, net-0 energy comsumption, net-0 water use, and net-0 carbon emissions.

(Image: Sketch from aplanning session, from the Oregon Sustainability Center website)

Shanghai Tower planned for 2014

In The Master Builder, urbananatomy.com reports on the Shanghai Tower, which will be the world's second tallest building when completed in 2014.

This interesting interview with the design architect, Marshall Strabala discusses the cultural context of the project, technical aspects of the tower, and some of the sustainable features contributing to the building's LEED Gold pre-registration.

Green Challenge: Are we really making better buildings?

LEED Sets New Standard; Critics Question If It's Living Up to It (Architecture Record online, 1/30/2011) reports on questions coming from within the design and construction industry regarding the true beneifits of standardized green design. Is a building designed to LEED standards really more energy efficient than one that is not?

More info:

• USGBC, LEED Targeted by Class-Action Suit
• Lies, Damn Lies, and... (Another Look at LEED Energy Efficiency)

LEED Pilot Credits Program

USGBC's LEED credit piloting program provides a framework for testing and refining proposed new prerequisites and credits prior to their formal introduction into the core LEED rating systems. Building teams interested in making use of pilot credits can apply to participate in the program. Current pilot credits include:

Life Cycle Assessment of Building Assemblies and Materials

This credit seeks to encourage the use of environmentally preferable materials based on life-cycle analysis scoring. An approved Environmental Impact Calculator is used to assess materials in various assembly types, such as columns and beams, floors, exterior walls, windows, etc. Results of this assessment are transferred to a second calculator, the USGBC Credit Calculator, to determine a life-cycle impact score and number of LEED points to be awarded. Up to 5 points, plus 2 additional innovation points can be achieved.

A this time, the approved environmental impact calculator is the Athena Institute's Eco-Calculator for Assemblies.

PBT Source Reduction: Dioxins and Halogenated Organic Compounds

This credit is intended to discourage the use of materials classified as persistent bioaccumulative toxic chemicals (PBTs). PBTs are considered to have significant adverse health effects on humans because they are toxic, long-lasting, and given to accumulating in the biological food chain. The PBTs specifically targeted by this credit are halogenated organic compounds. Examples include plastics containing chlorine or fluorine (polyvinyl chloride, PVC, being perhaps the most commonplace example) and brominated or halogenated flame retardants.

This pilot credit appears to signify the USGBC's change in position regarding the environmental suitability of PVCs for use in building construction. See this blog's previous discussion of this issue in Complexities of Sustainability, November 2007.

Medical and Process Equipmenet Efficiency

This credit encourages the purchase of energy efficient medical and other types of equipment.

Innovative Ventilation

This credit encourages the use of mechanical or natural ventilation systems that improve occupant comfort and well-being while reducing energy consumption in comparison to conventional systems. Example potential technologies include displacement ventilation systems, low-velocity ventilation systems, under-floor air delivery systems, and natural ventilation designs.

Preliminary Integrative Project Planning & Design

This credit is intended to encourage innovative strategies for achieving integrative, cost-effective green design and construction methods. Two credits are included, the first applied to the programming and pre-design phases of a project, and the second for the following design and construction phases. These credits require early identification of LEED rating goals, institution of cross-disciplinary design practices, performance based incentives, and other sustainable building design best practices.

More Info

• LEED Pilot Credit Library
• EPA Persistent Bioaccumulative and Toxic (PBT) Chemical Program

What's In a Green Highrise?

 MetroTower III aims to reach new heights for green building (Journal of Commerce, December 4, 2008) describes this 25-story tower, USGBC's first Canadian pre-certified LEED Platinum core and shell commercial building structure.

Attaining LEED certification will purportedly add $1.5 million to the $170 million project and is expected to reduce annual operating costs by $75,000.

Among the building's green attributes are:

• Large windows, light sensors, heat exchangers, and reliance on renewable energy sources, contributing to energy conservation
• A curved southwest facade to maximize daylight in a nearby outdoor plaza
• Low-e glass that admits more daylight, but less heat
• Collection of rainwater for landscape irrigation and flushing of toilets
• Drought-resistant landscaping and restoration of native habitat
• Replacement of trees removed for construction
• Access to public transportation
• Regional materials and materials with recycled content
• Recycling of construction waste
• Certified woods for finish carpentry
• Shower and lock-up facilities for bicycle commuters

The developers claim a 35% reduction in the building's carbon footprint.

Complexities of Sustainability

LEED as the Definition of Sustainability
Can LEED Survive the Carbon-Neutral Era (Metropolis, November 2007) discusses the growing acceptance of the US Green Building Council LEED rating system while also considering future challenges to its relevance:

• USGBC claims 40,000 LEED-accredited professionals. The organization has certified only roughly 1000 buildings since its inception.
• A recent study by construction consultant Davis Langdon claims that LEED-certified buildings, at least up to the Gold certification level, need not cost more than conventionally designed buildings. Fiona Cousins of ARUP New York estimates it can cost $100,000 in service fees to document building performance for LEED.
• Until June of this year, buildings could achieve LEED certification without receiving any energy performance points associated with reductions in carbon emissions.
• ASHRAE, in conjunction with USGBC and others, is promoting its Advanced Energy Design Guides which target energy savings of 30% over current national  standards. ASHRAE intends to introduce similar mandatory standards by the year 2012. ASHRAE and the AIA are proposing national legislation that would require new buildings to be fully climate-neutral by the year 2020.

The article also discusses the pros and cons of the LEED "checklist" methodology for defining sustainability, in contrast to more ntegrated approaches to sustainable building design. And the article speculates on the possibility of LEED's broad definition of sustainability, which includes considerations of site and community development, materials and resources, and indoor air quality, being preempted in the future by the need to focus more narrowly on the conservation of water and energy.

Separately, The Battle for Green Building (Springfield Business Journal, 12/11/20067) discusses the Green Building Initiative's Green Globes sustainable building certification program, an alternative to the better know LEED. Though there are many similarities between these two programs, Green Globes is reportedly distinguished by its pending certification by the American National Standards Institute, and its lower implementation cost than LEED.

PVC as a Sustainable Material
The USGBC's February 2007 Assessment of the Technical Basis for a PVC-Related Materials Credit for LEED is the that organization's final report on the contentious issue of the use of PVC materials in building construction.

USGBC has been considering this issue since at least the year 2000. The Assessment looks at four common PVC applications: siding, drain/waste/vent piping, resilient flooring, and window frames. Each is compared with common alternatives, for example in the case of siding, with aluminum, wood, and fiber-cement. Materials are evaluated on a number of bases:

• Conventional life-cycle assessment in which all the resource and pollution inputs and outputs associated with the material-- beginning with its harvesting or extraction and ending with its reuse or disposal at the end of its service life--are considered. Impacts on both human health and the environment are included.
• Extended end-of-life analysis in which potential PVC dioxin emissions from backyard burning and accidental landfill fires are considered. Given the large uncertainties in the data for this scenario, upper, middle, and lower range estimates were evaluated.
• Risk assessments of the adverse human health effects due to exposure to toxic compounds generated throughout the life cycle of the materials.

The conclusion: No single material shows up as the best across all human health and environmental impact categories, nor as the worst.

The assessment's results resist simplistic conclusions. Material rankings vary depending on how environmental and human health impacts are prioritized. In other words, a choice of one material over another may benefit human health while increasing adverse effects for the environment, or vice-versa. Rankings also vary with the product category. Only in the resilient flooring category do PVC products rank consistently higher in both adverse human health and environmental effects than alternative materials (linoleum and cork).

Meanwhile, Schwarzenegger Bans PVC Additive In Toys (Healthy Building Network, October 25, 2007) reports that, despite claims made by the Vinyl Institute regarding the safety of PVC in children's toys, the state of California has passed legislation prohibiting the use of phthalates, a PVC plasticizer, in products intended for babies and children under three years of age. The article goes on to state:

Like the human carcinogens vinyl chloride and dioxin, phthalates are uniquely associated with PVC. It is this triple threat from PVC that distinguishes it as the worst plastic for environmental health and green building. Regrettably, there are still few restrictions on the use of vinyl in green buildings.

Evolving Measures of Material Sustainability
Shedding Light On The Pharos Project (Eco-Structure, December 2007) describes the Pharos Project, an ambitious building products rating program under development by the Healthy Building Network.

The Pharos Project is touted as a database of building materials intended to allow a more comprehensive and sophisticated evaluation of the sustainable attributes of materials than is currently offered by other rating systems. Its unique framework covers a broad range of health, environmental sustainability, and social justice criteria.The Project will also host a Wiki and online forums.

A visit to the Project's web site leaves one questioning whether the Project is alive and well. The most recently dated content appears to be from November of 2006. According to Eco-Structure, the next working version of the Project is scheduled for release in the spring of 2008.

Measures of Sustainable Buildings
Energy Performance Data Largely Lacking (ENR, November 12, 2007) reports that, despite the attention being given to green building design, there is a lack of standards for collecting and analyzing building energy performance data, and, though newer buildings may be designed to be more energy efficient than older buildings, building energy use overall continues to climb:

• According to the U.S. Department of Energy, commercial buildings consumed 18 quads (18 quadrillion BTUs) in 2004, and are projected to consume 25 quads--almost a 40 percent increase--by the year 2030. The largest part of this jump is attributed to increased use of electrical equipment and the increased cooling loads that result.
• Between 1980 and 2000, energy use per square foot in commercial buildings increased by roughly 25 percent.

LEED certification does not necessarily correlate with reduced building energy consumption. On the one hand, Seattle's LEED-Silver Alley24 mixed-used development, completed in 2006, is reportedly close to achieving a 50 percent targeted reduction in CO² emissions. On the other hand, Seattle's new City Hall, also LEED-Silver, completed in 2003, is separately reported as consuming significantly more energy than the larger, older building that it replaced.

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.