Resource

Buildings Materials Backgrounder

July 4, 2004

The Big Picture

According to U.S. Government data, buildings account 60% of the raw materials used in the U.S., and 40% of non-industrial solid waste. Unlike some industries, in which there is a move toward dematerialization, the building industry will always need materials. So the question becomes: what are the best materials and products to use? To address this question one has to consider the overall life cycle of the materials and of the facility and building site as a whole.

Building materials choices are important in sustainable design because of the extensive network of extraction, processing and transportation steps required to process them. One of the most effective strategies for minimizing the environmental impacts of material use is to reuse existing buildings. Rehabilitation of existing building shells and non-shell components reduces solid waste volumes and diverts these waste volumes from landfills. It also reduces environmental impacts associated with the production and delivery of new building products. Reuse of an existing building minimizes habitat disturbance and typically requires less infrastructure such as utilities and roads.

Context

Ecological decisions about materials choices have tended, until recently, to be driven by isolated, hot-button issues: avoid wood from old-growth forests, use recycled materials, use local materials. These issues are important, but they sometimes drive choices that are short sighted. While some sources of wood should be avoided, wood in general is a relatively low-impact material to use, so avoiding wood entirely tends to increase overall environmental impacts. There is a clear need for methods and tools that make it feasible for building professionals to look at the issues holistically, but for the most part these tools are still in their infancy.

Over the past decade or so, an increasing number of public and private waste management operations have begun to reduce construction debris volumes by recycling and reusing these materials.

Getting Down to Business

Some businesses, agencies, and designers have long been proactive in pursuing green options for their buildings, and have relatively sophisticated systems in place. For others, green specifications and procurement policies for building materials are largely driven by government mandates, incentive programs, and the LEED Rating System.

The architecture and engineering firm HOK, Inc. develops aggressive green specifications for cutting-edge projects, and then draws from them to green its company-wide standard specifications when possible. It has also incorporated “green defaults” to go into all specifications.
The State of California is using a specification section 01350 for green materials that includes comprehensive, health-based guidelines for indoor emissions from products based on actual emissions testing of those products.
Herman Miller (among other product manufacturers) is using the cradle-to-cradle protocol from McDonough Braungart Design Chemistry (MBDC) in its product development process. This protocol promotes the use of products that are safe for humans and the environment, and recyclable in perpetuity through either biological or industrial metabolisms.
The KSBA Architects office building is a LEED-certified pilot project located in the Lawrenceville section of Pittsburgh. The entire shell of the 1888 building was reused as well as 90% of interior millwork. New components were installed to update the interior spaces, including a raised access floor with HVAC and modular cabling, indirect lighting and ergonomics. The building now serves as a state-of-the-art information and technology headquarters for an architectural firm.

Key Players

The U.S. federal government has several programs in place, including overall guidance on environmentally preferable purchasing (EPP) based on Executive Order 13101 and others; recycled-content rules in the Comprehensive Procurement Guidelines (CPG); the ENERGY STAR program for products, equipment, and buildings; and a new initiative in the Department of Agriculture promoting the use of bio-based products.
The U.S. Green Building Council’s LEED Rating System encourages the use of products and materials with a wide range of green attributes. While each LEED credit addresses a single attribute in isolation, a design team pursuing LEED certification has to consider multiple attributes of materials as it seeks to achieve a range of credits.
Nonprofit organizations create standards and certify products that comply with those standards. Examples include Green Seal (for overall environmental performance) and GreenGuard (for indoor air emissions from products).
For-profit certifiers, such as Scientific Certification Systems, can provide third-party certification of environmental claims based on single attributes or comprehensive assessments.
Various publishers offer green product directories. Many are supported primarily by advertising. A few, including the GreenSpec Directory from BuildingGreen, Inc., carry no advertising.
Of the handful of systems for certifying environmentally friendly forest practices, the most widely respected program is by the international Forest Stewardship Council. Organizations that certify forests and wood product suppliers according to FSC guidelines include the SmartWood program of the Rainforest Alliance and Scientific Certification Systems, Inc.

The Upside

Whether through regulation or market demand, the preference for low-impact materials is spreading. Organizations that are proactive in their purchasing and specification of green materials have a marketable expertise. Due to the enormous quantity of materials that is used in buildings, the environmental impact of green purchasing in this sector is huge.

When new materials are used in buildings, it is important to consider different sources. Salvaged materials can substitute for new materials, save on material costs and perhaps add character to the building. Recycled content materials reuse waste products that would otherwise be deposited in landfills. The use of local materials supports the local economy and reduces the impacts of transportation. The use of rapidly renewable materials and third-party certified wood minimizes the impact of natural resource consumption to manufacture new building materials.

Reality Check

While the demand is clear for comprehensive, life-cycle-based materials selection tools, the available resources are still quite limited.

Beware of life-cycle analysis tools that appear to provide high levels of accuracy in their results — LCA is a very rough science at this point.
When comparing products, be sure to account for the ramifications of each option on the overall assembly in which it will be installed. Vegetated roof systems may require beefed-up structural systems, for example.
While green alternatives may perform as well as — or even better than — conventional product choices, they have their own installation and maintenance requirements. If installers and facilities staff are not trained and empowered to support these products, the products can fail through no fault of their own.
Many greener alternatives come from small and entrepreneurial companies and may require special ordering and advance warning to meet delivery schedules.
Beware of product substitutions that may not meet a project’s environmental goals. Even government agencies should be able to specify products by name as long as the performance requirements are also provided so that alternatives can be considered.

Action Plan

Designers and owners pursuing LEED certification need a process for identifying LEED-compliant materials and tracking submittal requirements related to those materials.
Review your model specifications regularly to ensure that they encourage greener choices wherever possible, and don’t require inappropriate choices (such as virgin materials or CCA-treated wood).
Designate key personnel to become trained in the use of life-cycle analysis tools as they become more relevant and sophisticated.
When evaluating life-cycle information from companies, rely only on specific information that can be compared to other sources, and seek a full disclosure of all the assumptions that might affect the data.
Develop your own in-house database of green materials and products, or contract with an organization that can make such a database available on your corporate intranet.
Visit existing buildings to see how materials perform, and track your own organization’s experiences with alternative products (both positive and negative).

Leads

Building for Environmental and Economic Sustainability (BEES)

Easy-to-use program for selecting cost-effective, environmentally preferable building products.
National Institute of Standards and Technology

Offers life-cycle analysis software.
Environmental Building News

A monthly newsletter and website with comprehensive overview articles on materials choices and detailed product reviews.
GreenSpec Directory

Online directory of environmentally preferable building products.
U.S. EPA’s Environmentally Preferable Purchasing Program

Program from the U.S. EPA promotes environmentally responsible purchasing in the U.S. federal government.
Oikos Green Building Source

Features a database on green building products.
Green Seal

This nonprofit organization sets standards for green products and offers product recommendations.

Bottom Line

Building materials that are currently selected based on a single green attribute will be increasingly scrutinized for their overall life-cycle impacts. Manufacturers are already using life-cycle data to inform their product development, and they are beginning to find acceptable ways to make that information available in the marketplace. But there are still many wrinkles to work out in this field, and owners, designers, and specifiers have to stay well informed to make effective use of this evolving universe of information.

Special thanks to Nadav Malin, editor of BuildingGreen.com and Environmental Building News, for his contribution to this article.