Can I convert an existing small basement window to a code-compliant egress window in my Moncton home?

Yes, converting an existing small basement window to a code-compliant egress window is one of the most common basement renovation projects in Moncton, and it is often more affordable than cutting an entirely new opening because part of the foundation has already been penetrated. That said, the existing opening almost certainly needs to be enlarged significantly to meet NB Building Code requirements.

The NB Building Code requires every basement bedroom to have an egress window with a minimum clear opening of 3.8 square feet (0.35 m²), and the sill height cannot exceed 1500mm from the finished floor. Most older Moncton homes built in the 1960s through 1990s have small basement windows — typically 30 by 16 inches or similar — that fall well short of this requirement. A code-compliant egress window usually needs to be around 48 inches wide by 36 inches tall or a similar combination that meets the 3.8 square foot minimum.

Converting the existing window involves cutting the foundation wall to enlarge the opening. In Moncton, most homes from the 1970s onward have poured concrete foundations, which respond well to concrete cutting with a diamond-blade wall saw. Older concrete block foundations require more careful work to avoid destabilizing the surrounding blocks. Either way, a steel lintel must be installed above the enlarged opening to carry the load that the removed foundation section was supporting. This is structural work that requires a building permit and proper engineering.

The process typically involves removing the existing window, marking and cutting the enlarged opening with a concrete saw, installing the steel lintel, setting the new egress window and frame, waterproofing around the exterior, and installing a window well with proper drainage. In Moncton's sandy and silty soils, drainage around the well is generally easier than in clay-heavy areas like Saint John, but a layer of clear crushed stone and a drain connection are still essential to handle spring snowmelt.

Expect to pay $2,500-$5,000 for a complete conversion including the window, cutting, lintel, well, and waterproofing. The lower end applies when the existing opening is already close to the required size and the foundation is poured concrete. The higher end covers situations where the opening needs major enlargement, the foundation is concrete block, or the well requires significant excavation and drainage work.

A building permit is required in Moncton for this work — the city's building inspection department typically processes permits within 1-3 weeks, and you will need a framing/structural inspection after the lintel is installed and a final inspection when complete. Do not skip the permit. If you finish a basement bedroom without a code-compliant egress window and proper permits, it cannot legally be called a bedroom, which affects your home's resale value and creates a life-safety hazard.

This is strictly a professional job — cutting a foundation wall requires a diamond-blade concrete saw, structural knowledge for the lintel sizing, and proper waterproofing around the new penetration. Get at least three quotes from local basement contractors, as pricing in Moncton varies 30-40% between contractors for the same scope of work.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• Thirty Four Renovations
• Gionetterenovations