What is the minimum depth of a window well for an egress window in New Brunswick when the top of the window is below grade by more than 44 inches?

When the top of your egress window is more than 44 inches (1,100mm) below grade, the window well must be deep enough to provide a minimum 550mm (approximately 22 inches) of clear space in front of the window opening.

This is the projection dimension required by the National Building Code of Canada (NBC), which New Brunswick adopts and enforces — the well must extend at least 550mm outward from the foundation wall to give an occupant enough room to open the window, climb through, and escape. The well also needs to be wide enough to accommodate the full width of the egress window opening, with no obstructions blocking the clear opening area.

The depth of the well below grade is determined by your window placement, but the critical measurement inspectors focus on is that 550mm clear projection from the wall face to the front of the well. If your window sits deep — more than 1,100mm below the exterior grade — you're also looking at a well that will collect significant water. Drainage at the base of the well is not optional in New Brunswick. A gravel bed (minimum 150mm of clear stone) at the bottom of the well, connected to a drainage path away from the foundation, is required. Without it, the well becomes a water collection basin that drives hydrostatic pressure directly against your foundation wall at the window opening — one of the more common sources of water entry in NB basements.

NB-specific considerations matter here. With frost depth reaching 1.2m in southern NB and 1.5m in the north, deep window wells are exposed to significant freeze-thaw movement. The well liner (typically galvanized steel or heavy-duty polyethylene) must be properly anchored and the surrounding backfill compacted to resist heaving. In Saint John's heavy clay soils especially, poorly drained window wells are notorious for trapping water and pushing it through the foundation opening. In Moncton's sandier soils, settlement around the well can cause the liner to shift and create gaps at the foundation wall.

Practical tips before installation:

• Confirm your window well dimensions with your local building department or RSC before cutting — Moncton, Fredericton, and Saint John have their own inspectors, rural areas go through Regional Service Commissions
• Egress window installation requires a building permit — cutting through a foundation wall is structural work
• Budget $2,500–$5,000 per egress window including the foundation cut, well, drainage, and window unit
• Install a well cover (clear polycarbonate) to reduce water and debris accumulation while still meeting egress requirements — covers must be openable from inside without tools

This is work to hire a professional for. Cutting a foundation wall incorrectly can compromise structural integrity, and improper well drainage will create a chronic water problem. New Brunswick Basements can match you with a local contractor experienced in egress window installations — get matched for a free estimate through the New Brunswick Construction Network.