Our surveyor from way back at the beginning of this project returned today to mark the “outsets” (I think that’s what they were called). He puts stakes around the property noting how far from each stake the house begins. This includes one marking how far down the bottom of the footings need to be.

The footing depth is absolutely critical for several reasons:

1. If the house is too deep, the outging sewer connection will not flow properly. (It won’t be installed at all, actually.)
2. If the house is too high, we’ll be in violation of the building code which limits the height of a house to 10m above grade at the front wall of the house.
3. The footings must rest on undisturbed soil. There is no acceptable way to recompress the soil once it has been disturbed. If the footings did sit on disturbed soil, the house (especially one made of concrete) could tilt and/or sink.

The surveyor marked the bottom of the footings based on traditional building practices because the documenation we provided didn’t stipulate exactly what was going on beneath the surface of the basement floor.

For our project, we have some extra height requirements because our footings are 10″ deep (typically 6″), we have 2″ of insulation between the ground and our basement floor, and our floor itself is 4″ instead of 3″ thick. The net result is an extra 7″ of depth to the bottom of the footings.