Structural engineering may not be top of mind when it comes to “Green Building Design.” However, at a recent SEOC speaking engagement in Louisville, I had the opportunity to bring structural engineering to the forefront. Here are a few highlights specifying how we contribute to earning several of the Materials and Resources Credits (MR Credits) necessary for LEED certification.
If reusing an existing building, consider how the existing walls can earn you LEED points. When Luckett & Farley works with a team to reuse 75% of an existing building’s walls, floors and roof we can earn one credit. If 95% is used then two credits are earned. Maintain 50% of interior non-structural elements and one credit is earned. The intent is to reduce demolition waste and make good use of the existing structures. The structural engineers will then use innovative ways to strengthen the existing structures to adapt to new occupancies.
The intent of these credits is to reduce the demand for virgin materials and reduce the demolition debris going into the waste stream. When 5% of total material used on the project is reused, one credit is earned. At 10% two credits are earned. The structural engineers can contribute by specifying crushed concrete or CMU for engineered fill, using salvaged wood or steel members in the design.
For the same reason you recycle at home, structural engineers use products with recycled content to reduce extraction and processing of virgin material. This, in turn, uses fewer natural resources and eliminates the high energy consumption and increased carbon foot print necessary for creating new content. Most of the steel produced in the U.S. uses high recycled content. Other materials such as, fly ash in concrete, utilize byproducts that could have gone into the waste stream, but now are being used as a building product. These materials can contribute to more credits.
Structural engineers using local products in their design help the local economy and reduce fuel consumption otherwise used for long distance transport. The structural designs should include local species of wood, local aggregates in concrete and specifications should encourage using local suppliers of the products.
The intent is to encourage environmentally responsible forest management by requiring a minimum 50% of the wood based material to be certified by Forest Stewardship Council (FSC). The FSC ensures specific wood comes from environmentally responsible sources. The structural specifications for wood structures should include the need for using the certified wood.
So the next time you find yourself in a green day dream of natural lighting, high efficiency fixtures, and rain gardens, don’t leave out the backbone of your new green building: structural.