Foundation
There are three types of mainstream residential building foundations: full basement, raised floor and slab-on-grade. All have different attributes and some make better green building choices than others.
Full Basement Foundation
Most popular in the northern U.S., full basement foundations offer added storage and living space and a place for mechanicals, such as boilers, water heaters and other systems.
Basements contribute to green building in several ways. A well-insulated full basement helps reduce energy costs and also provides comfort underfoot because the floor is warmer. Because a full basement has a wood sub-floor, it gives slightly, reducing fatigue and increasing comfort. A wood sub-floor also allows the installation of natural wood floors or carpeting without the need for toxic adhesives or mastics, which can outgas into the living environment, especially in the early months after construction.
Green building wood products used in full basements:
Raised Floor
Like full basement foundations, raised floor foundations have a wood sub-floor for superior comfort and the installation of flooring materials without adhesives. But because raised floor foundations are built on grade with the house resting on a perimeter foundation and piers, they are much less expensive to build than full basements. Popular in southern climates below the 36th Parallel, raised floor foundations are an ideal green building choice because they greatly reduce the need to manufacture, transport and install large amounts of concrete.
Read more about raised floor foundations:
Green building wood products used in raised floor foundations:
Slab-on-Grade Foundation
Slab-on-grade foundations are a poor green building choice because they require large amounts of concrete. The mining and manufacturing of cement and gravel are harmful to the earth and result in significant greenhouse gas emissions, while transporting heavy concrete wastes large amounts of energy.
Because the sub-floor of a slab-on-grade foundation is made of concrete, it is often cold, and its rock hard surface has little give which reduces comfort. While wood floors can be “floated” on concrete slabs, carpet and other flooring materials must be glued in place, often with products that are toxic.
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