On Grade

Prompt

What is the most conventional way to build on a flat site?

Findings

When we build a home On Grade, we take advantage of a flat building pad to both structure and help insulate our floor. This can save time and money, and is by far the most common way to build on a flat site. Building directly on the ground allows for flush transitions from indoors to outdoors, but requires careful detailing to prevent water infiltration and flooding. We can use a concrete-free slab to reduce the carbon footprint of this method (though the strip footings and stem walls are usually still poured with concrete). Water, sewer, and power lines buried below the slab can cause challenges in sequencing construction, and will be difficult to service over the lifespan of the house. Preplanning the sub-slab layout is essential to a successful build.