Obtaining Green Building Certification
Leadership in Energy and Environmental Design (LEED®) is a point rating system devised by the U.S. Green Building Council (USGBC) to evaluate the environmental performance of a building and encourage market transformation towards sustainable design. The system is credit-based, allowing projects to earn points contributing to a range of environmental strategies. There are numerous LEED rating systems for various project types, including New Construction, Schools, Commercial Interiors, and Homes.
Points are assessed for environmentally friendly actions taken during the planning, construction and use of a building. LEED was launched in an effort to develop a “consensus-based, market-driven rating system to accelerate the development and implementation of green building practices.” The program is not rigidly structured; not every project must meet identical improvements to qualify.
Cement Manufacturing Transparency Reporting
As an early industry sector responder to evolving green building requirements, PCA and its members were among contributors to the creation of 2014 Product Category Rules (PCR) on North American cements published by ASTM, Product Category Rules For Preparing an Environmental Product Declaration for Portland, Blended Hydraulic, Masonry, Mortar, and Plastic (Stucco) Cements. To see or download the PCR, click here.
For detailed information on cement sustainability manufacturing read the PCA Report on Sustainable Manufacturing.
Storm Water Management
Concrete has played a significant role in conventional surface water management by providing conveyance and treatment infrastructure that is durable and impermeable. With the movement toward managing water on site, concrete continues to play a major role, as it is frequently the material of choice to help construct flow control and treatment facilities on site.
With sustainable design, there is considerable interest in mimicking pre-development hydrologic functions as much as possible. This has resulted in a focus on using strategies that emphasize conservation and use of on-site natural features integrated with small-scale hydrologic controls. Combined these strategies are known as Low Impact Development or LID. Four LID strategies use concrete:
Pervious Concrete: Pervious concrete is cast-in-place using a mix that leaves significant voids allowing water to percolate through.
Permeable and Grid Paver Systems. Interlocking pavers can allow water to pass through gaps in the blocks or in grid openings designed to provide both structural support and space to hold either grass or gravel.
Green Roofs. Vegetated roofs absorb and release water slowly through evaporation and delayed run-off.
Rainwater Catchment Systems. Concrete cisterns capture water from rainfall and store it for later use in non-potable (not for drinking/eating) use, either toilet flushing or irrigation. Treatment systems can make it suitable for drinking, bathing, etc. if warranted.
In addition to providing a more naturalistic solution to stormwater management, LID can reduce the need for large (and frequently expensive) stormwater facilities such as detention ponds. These strategies increase infiltration and can help achieve points under LEED Sustainable Sites Credit 6.
Concrete and LEED
Using concrete can increase the number of points awarded to a building in the LEED system. Below are suggestions for earning LEED points through the use of cement and concrete products. The USGBC web site, www.usgbc.org, contains a downloadable ”letter template“ that greatly simplifies the documentation requirements for LEED. For more details, see Concrete Contributions to LEED® v4, 2013.
LEED is a voluntary program; however, obtaining a LEED certification projects a positive environmental image to the community. Additionally, meeting many of the green building practices can result in energy and cost savings over the life of the structure. Other advantages include better indoor air quality and increased amounts of daylight. Studies have shown that workers in these environments have increased labor productivity, job retention, and days worked. These benefits contribute directly to a company’s profits because salaries are the largest expense for most companies occupying office space—about ten times higher than rent, utilities, and maintenance combined. In addition, students in these environments have higher test scores and lower absenteeism. Retail sales are higher in day-lit buildings.
Support for green buildings has increased rapidly each year during the last ten years. Many cities and states either provide tax credits or grants for green buildings, or require green building certification for public buildings. The U.S. government is adopting green building programs similar to LEED through the General Services Administration, the U.S. Army, the U.S. Navy, the Department of State, the Department of Energy, and the Environmental Protection Agency.
The LEED Green Building Rating System for New Construction, promotes environmentally sustainable buildings for the improvement of outdoor and indoor building quality, the conservation of resources, and the reduction of waste during the building process. Concrete can be used in conjunction with the LEED program to earn certification. Detailed information on the LEED program and project certification process is available on the USGBC web site, www.usgbc.org.
Five Ways Concrete Helps Build Green
1. Concrete creates sustainable sites.
2. Concrete assemblies can enhance energy performance.
3. Concrete contains recycled materials.
4. Concrete is manufactured locally.
5. Concrete builds durable structures.
Main LEED Credit Categories
- Integrative process
- Location and transportation
- Sustainable sites
- Water efficiency
- Energy and atmosphere
- Materials and resources
- Indoor environmental quality
Each category is divided into credits. Detailed information on the LEED program and project certification process is available on the USGBC web site, www.usgbc.org
. The program outlines the intent, requirements, technologies, and strategies for meeting each credit. Credits are broken down into individual points. Additional points can be earned for innovation or exceptional environmental performance, and the use of a LEED accredited professional on the project team.