How do I install a window well in my Ottawa basement?

Installing a window well in your Ottawa basement is a manageable project for a handy homeowner, but it involves excavation, drainage, and potentially the Ontario Building Code — so it's worth understanding the full scope before you dig.

A window well allows natural light and egress access to basement windows, and in Ottawa's climate, proper installation is critical to prevent water infiltration and frost heave damage.

Planning and Permits

Before you touch a shovel, check whether your project requires a permit. If you're installing a window well alongside a new or enlarged basement window — especially an egress window for a bedroom or secondary suite — you'll almost certainly need a building permit from the City of Ottawa (613-580-2424 or ottawa.ca/building). The Ontario Building Code (OBC) requires egress windows to have a minimum 0.35m² clear opening, with no dimension less than 380mm. If you're simply replacing an existing well without changing the window, a permit may not be required, but it's always worth confirming.

The Installation Process

The actual installation involves several key steps. First, excavate around the foundation wall to a depth about 15–20cm below the bottom of the window frame. In Ottawa, your frost line sits at 4 feet (1.2m), so if your window sits near that depth, drainage becomes especially important. Once excavated, position the window well (typically galvanized steel or heavy-duty polyethylene) against the foundation wall and secure it using masonry anchors or tapcons rated for concrete.

Drainage is the most critical element of a properly functioning window well. At the base of the excavation, lay a minimum 15–20cm layer of clean crushed gravel (¾" clear stone works well). This allows water to percolate away from the foundation rather than pooling against your wall. If your soil has poor drainage or you're in a low-lying area of Ottawa, consider running a perforated drain tile from the base of the well to your weeping tile system. Skipping this step is the #1 reason window wells cause basement water problems.

Once the well is anchored and gravel is placed, backfill the sides carefully, sloping the grade away from the foundation at roughly 1" drop per foot for the first 6 feet. Seal the joint between the window well flange and your foundation wall with a quality hydraulic cement or polyurethane sealant — not standard caulk, which won't hold up to Ottawa's freeze-thaw cycles.

Costs in the Ottawa Market

For a straightforward window well installation (assuming the window itself is existing):

• Basic DIY materials: $150–$350 (well unit, gravel, anchors, sealant)
• Contractor-installed (well only): $600–$1,200
• Full egress window + well installation: $2,500–$4,500, depending on excavation depth and window size

When to Call a Professional

If your installation involves cutting a new opening in your foundation wall, that work should be done by a professional — improperly cut openings can compromise structural integrity. Similarly, if you encounter your weeping tile system during excavation, stop and consult a contractor before proceeding. Disturbing drainage systems without understanding your foundation's waterproofing setup can cause serious problems down the road.

For basement-specific concerns like waterproofing integration or egress window installations as part of a secondary suite, our dedicated team at OttawaBasements.com specializes in exactly this type of work.

If you'd like a professional assessment of your window well project, Justyn Rook Contracting offers free estimates — we can confirm what permits apply to your specific situation and make sure the installation is done right for Ottawa's climate.