Below Grade Walls

Manitoba Building Code – Depth of foundation wall insulation

The Manitoba Building Code requires that basement and crawlspace walls be insulated from the underside of the subfloor to a minimum of 2.4 meters (8 feet) below the ground level or to the floor of the space, whichever is less (the ground level in a crawlspace is deemed to be the floor).

In most new homes, the insulation should extend down to the basement floor. If your new home will have an unusually deep basement because of a suspended wood floor or other reason, it isn't mandatory for the insulation to extend all the way to the bottom of the foundation wall if the bottom is more than 2.4 meters (8 feet) below grade.

Limiting the depth of insulation required reflects that the heat loss through a foundation wall tends to decrease with the distance below grade.