Egress Window Installation — Toronto GTA OBC 9.9.10 Compliant

An egress window installation is the most regulated single component in a Toronto basement renovation. If the basement is being converted into a legal secondary suite, an additional bedroom, or any habitable space below grade, Ontario Building Code Section 9.9.10 mandates a minimum egress window in every bedroom and sleeping area. The window must provide an unobstructed open area of 0.35 square metres minimum, with a minimum clear dimension of 380 millimetres in any direction, and a maximum sill height of 1.5 metres above the finished floor. A regular slider with a tight 24-by-36-inch opening does not satisfy this — it is one of the most common code-compliance failures in older Toronto basement renovations.

At RenoHouse the 2026 GTA pricing for egress window installation lands at $5,000 to $6,500 for an easy-access poured-concrete cut (existing window enlargement only), $8,500 for a standard cut with new window well and proper drainage, and $12,000 to $14,000 for a complex install requiring P.Eng. underpinning review, clay-soil shoring, or heritage masonry restoration.

What's involved in a code-compliant egress window installation

A standard mid-tier egress window installation at RenoHouse runs through the following sequence: site inspection and feasibility review (including a check of the foundation type — poured concrete versus concrete-block versus rubble-stone, since each material has materially different cut difficulty and structural risk), application for a Toronto Chapter 363 building permit with P.Eng. seal on the structural design where the cut exceeds the lintel-tolerance for the wall thickness, MOL Reg 278/05 DSS check for any asbestos-containing materials around the work zone, layout and marking of the new opening, installation of temporary shoring on the inside of the wall to support the load above the cut (this is critical and is the most commonly skipped step on amateur installs), saw-cutting of the foundation wall with a wet diamond-blade circular saw with dust extraction, removal of the cut concrete block in chunks via dolly through the basement exit, installation of a new pressure-treated wood or steel lintel sized per the P.Eng. design, installation of waterproofing membrane (typically Blueskin SA or Henry 925) lapping over the lintel and onto the foundation wall, exterior excavation for the new window well, installation of a new pressure-treated wood or galvanised steel window well (with the steel-tread Bilco-style being our 2026 default), gravel fill in the well for drainage, connection of the well drainage to the home's weeping tile per OBC 9.14, installation of the new casement or slider window (sized to deliver the OBC 0.35 square metre open area at minimum), interior finishing of the rough opening, exterior caulking and trim, and a polycarbonate cover for the well to prevent leaf and snow accumulation.

The window itself is almost always a casement or hopper style, since these geometries deliver the full glazed area as open area more easily than slider styles. The window must include a safety-bar handle and must be operable from the inside without keys or tools per OBC 9.9.10.4.

Permits, OBC compliance, and inspection requirements

A Toronto Chapter 363 building permit is required for any egress window installation. The application package includes the architectural drawing showing the new opening, a structural drawing sealed by a P.Eng. when the foundation cut exceeds the load-tolerance for the existing wall, a site plan showing the window well location and drainage path, and the permit application form. Most Toronto applications are reviewed in four to six weeks.

OBC Section 9.9.10 is the controlling provision. The window must provide:

• Minimum 0.35 square metres of unobstructed open area
• Minimum 380 millimetres of clear dimension in any direction
• Maximum 1.5 metres sill height from finished floor
• Operable from the inside without tools or keys
• Unobstructed access path within the well

OBC Section 9.14 governs foundation drainage and is critical for window well installations. The well drainage must connect to the home's existing weeping tile, or to a dedicated sump where weeping tile is not present.

Inspections happen at structural framing (after the lintel is in place and the cut is finished), waterproofing and well drainage, and final after window install and exterior trim.

Cost factors, foundation type, and what drives premium pricing

The biggest cost drivers on a Toronto egress window are foundation material (poured concrete is the easiest cut, concrete block is mid, rubble-stone or heritage masonry is the most expensive), wall thickness, soil type (clay is harder to excavate than sand), depth below grade (deeper cuts require taller window wells and more drainage work), heritage status (Heritage Conservation District homes require Heritage Permit review under OHA Section 41/42, which adds 8 to 16 weeks and frequently dictates the window style and trim), and the number of egress windows in scope. A standard $5,000 to $6,500 install is a poured-concrete cut at standard depth with a modest well. A $14,000 install is a heritage masonry cut, with custom shoring, P.Eng. field review, and a stone-clad window well.

Why RenoHouse installs egress windows across the GTA

We have installed egress windows in Toronto (Cabbagetown, Riverdale, Annex, Forest Hill, Junction, Bloor West, Leaside, Lawrence Park, North York, Etobicoke, Scarborough), Mississauga, Vaughan, Markham, Richmond Hill, Oakville, Burlington, Aurora, King City, Caledon, and Brampton. Every project carries a $5 million liability policy, full WSIB coverage, a fixed-price written scope, P.Eng. structural review where the cut warrants it, manufacturer warranties on the window itself and the well (typically Bilco), and a two-year workmanship warranty on the cut, lintel install, waterproofing, and well drainage.

Our typical timeline runs two days for a clean poured-concrete cut with prefab well, three to five days for a standard install including waterproofing and drainage, and five to seven days for a complex heritage or underpinning scope. Call 289-212-2345 to schedule an on-site assessment and fixed-price written scope.

Toronto/GTA neighborhood considerations

• Forest Hill / Rosedale / Lawrence Park (heritage): Pre-war stone or double-brick foundation cut — wet-cut diamond-blade Stihl TS500i with vacuum extraction, structural lintel L3x3x1/4 angle iron + 8-inch-bearing block course rebuild. Typical $6.5K-$12K with engineering letter on bearing wall + permit.
• North York / Scarborough / Etobicoke (60s-70s): 1960s 8-inch poured-concrete foundation cut — straightforward diamond-saw cut, pre-cast concrete buck OR pressure-treated 2x10 buck, weeping-tile re-tie at sill drain. Typical scope $4.2K-$6.8K including OBC 9.9.10.1 compliant 0.35 sq m clear-opening Strassburger or PlyGem window.
• Mississauga / Brampton / Vaughan (90s+): 90s subdivision typically already-egress-compliant in finished basement; scope at unfinished retrofit is straightforward foundation cut + interior framing $3,800-$5,500. Weeping-tile cleanout $480-$680 add at trench reopening.
• Caledon / King City / Aurora (rural well): Rural lot — exterior window-well excavation generous, but rural overland flood-grading per OBC 9.14.6.1 means well depth at 1.2m minimum below grade with poly-resin Boman/Bilco well + drainage tile to weeping-tile or daylight sump. Typical $5.5K-$9.5K.
• Downtown condos: Almost never applicable — basement suite uncommon in high-rise. Townhome rear/side egress retrofit possible $4.5K-$7.8K but condo board approval per Section 98 alteration agreement mandatory.

Permit + license: OBC 9.9.10 Section 9.9.10.1 (egress) — clear opening 0.35 sq m minimum, no dim less than 380mm, sill height max 1.5m above floor. OBC 9.15.4 foundation cut requires engineering. Toronto Building Permit + structural review. WSIB + Working-at-Heights + Confined-Space (Reg 632/05) on basement cut.