Environmental Design + Construction - September 2008 - (Page S8)

CONCRETE EARNING POINTS CONCRETE CAN HELP EARN POINTS IN GREEN BUILDING RATING SYSTEMS. BY JENNI PROKOPY As the green building industry has evolved, so has the way concrete helps structures become more sustainable. Concrete can help earn points toward LEED certification in every major credit category. And as LEED-NC has evolved, the way it treats concrete has, too. One of the most striking changes is in the Materials & Resources category, says David Shepherd, director of sustainable development for PCA. “As green becomes more mainstream, what we did five years ago becomes more readily accepted as standard operating procedure,” he explains. Because USGBC’s mission is to transform the marketplace, he says, they raise the bar: where in earlier versions of LEED-NC a building could earn one point toward Credit 4.1 for using 5 percent recycled content, that has now doubled to requiring 10 percent recycled content, and the same goes for Credit 4.2 — doubled to requiring 20 percent recycled content. “That revision touts the impact of concrete,” explains Shepherd. “They’re changing how concrete is specified, and giving more value to that part of concrete that has the biggest impact…and encouraging use of supplementary cementitious materials.” PROJECT CHECKLIST: LEED — NEW CONSTRUCTION (NC) V2.2 HOW CONCRETE MAY CONTRIBUTE TO POINTS CREDIT CATEGORIES SUSTAINABLE SITES CREDIT 3 CREDIT 5.1 CREDIT 5.2 CREDIT 6.1 CREDIT 7.1 BROWNFIELD REDEVELOPMENT SITE DEVELOPMENT: PROTECT OR RESTORE HABITAT SITE DEVELOPMENT: MAXIMIZE OPEN SPACE STORMWATER DESIGN: QUANTITY CONTROL HEAT ISLAND EFFECT: NON-ROOF POSSIBLE POINTS 1 1 1 1 1 ENERGY AND ATMOSPHERE PREREQUISITE 2 CREDIT 1 MINIMUM ENERGY PERFORMANCE OPTIMIZE ENERGY PERFORMANCE REQUIRED 1-10 MATERIALS AND RESOURCES CREDIT 1.1 CREDIT 1.2 CREDIT 2.1 CREDIT 2.2 CREDIT 4.1 CREDIT 4.2 CREDIT 5.1 BUILDING REUSE: MAINTAIN 75 PERCENT OF EXISTING WALLS, FLOORS AND ROOF BUILDING REUSE: MAINTAIN 95 PERCENT OF EXISTING WALLS, FLOORS AND ROOF CONSTRUCTION WASTE MANAGEMENT: DIVERT 50 PERCENT FROM DISPOSAL CONSTRUCTION WASTE MANAGEMENT: DIVERT 75 PERCENT FROM DISPOSAL RECYCLED CONTENT: 10 PERCENT (POST-CONSUMER PLUS 1/2 PRE-CONSUMER) RECYCLED CONTENT: 20 PERCENT (POST-CONSUMER PLUS 1/2 PRE-CONSUMER) REGIONAL MATERIALS: 10 PERCENT EXTRACTED, PROCESSED AND MANUFACTURED LOCALLY REGIONAL MATERIALS: 20 PERCENT EXTRACTED, PROCESSED AND MANUFACTURED LOCALLY 1 1 1 1 1 1 1 ENERGY EFFICIENCY: E2 CITY HOMES One of the surest ways to earn points for energy efficiency in both residential and commercial construction is by using concrete in the building envelope. The Urban Project put this idea to use in its E2 City Homes development in Minneapolis. The two-story, four-unit residential complex used insulating concrete forms (ICFs) from Reward Wall Systems and was a LEED-H pilot project, earning Gold certification — and numerous awards. ICFs are stay-in-place forms made of foam, into which reinforcing steel and concrete are placed to create a sandwich wall with a high R-value, extreme durability and strength, sound-dampening qualities, insect resistance and fire safety. In the case of the E2 City Homes, ICFs helped the homes earn a low HERS rating, a measure of energy efficiency that impacts how a home earns points toward LEED certification. Donn Thompson, PCA’s program manager for residential technology, explains: If a home has a HERS rating of 100, it meets the minimum requirements of the model energy code — a prerequisite for LEED-H EA Credit 1.1. Each point reduction in a HERS rating refers to a 1 percent improvement in energy consumption above the prerequisite; the E2 City CREDIT 5.2 1 INNOVATION AND DESIGN PROCESS CREDIT 1.1 CREDIT 1.-1.4 CREDIT 2 PROJECT TOTALS INNOVATION IN DESIGN: REDUCE CEMENT CONTENT APPLY FOR OTHER CREDITS DEMONSTRATING EXCEPTION PERFORMANCE LEED ACCREDITED PROFESSIONAL 25 1 3* 1 *UP TO 3 ADDITIONAL POINTS CAN BE EARNED, MUST BE SUBMITTED AND APPROVED (NOT INCLUDED IN TOTAL) Homes had impressive HERS ratings ranging between 50 and 54. DURABILITY Concrete is built to last. Many concrete building systems can withstand the raw forces of wind, flood or fire. Because concrete structures are so solid and long lasting, their shells can often be maintained in reconstruction projects — earning points in the Materials and Resources category for Building Reuse Credits 1.1 and 1.2. The use of supplementary cementitious materials like slag cement and fly ash is growing every year, and in many cases these WWW.EDCMAG.COM materials serve to strengthen concrete mixes and increase their structural resistance to sulfate attack or alkali-silica reactions, and to help them perform better in freeze-thaw conditions. These qualities help buildings become more durable than ever — and the incorporation of recycled materials earns even more points toward LEED credits. THINKING LOCALLY: NORTH CENTRAL COLLEGE RES/REC CENTER In Naperville, Ill., students at North Central College are looking forward to the fall 2009 opening of a new fieldhouse with an indoor track, s8 http://www.edcmag.com/

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Environmental Design + Construction - September 2008 Contents Web TOC Editor's Note Newsline New and Notable Announcing the 2008 Excellence in Design Awards Award Winner: Yale Sculpture Building Snapshots: College and Universities Teach Sustainability Color ISH North America Green Continuing Education Special Section: Concrete Product Focus Marketplace and Classifieds Advertiser's Index Underwater Adventures

Environmental Design + Construction - September 2008

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