How much does an egress window cost?

Total installed cost: $2,000-$5,000 per window. This includes concrete cutting ($500-$1,500), excavation and window well ($500-$1,500), the window unit ($300-$800), installation ($300-$600), interior finishing ($200-$500), and permits ($100-$300). Factors that increase cost: thick poured concrete walls, deep window wells, rock in the soil, utility relocation, and premium window brands. This is not a DIY project — it involves cutting through the foundation wall and requires specialized equipment and expertise. What size does an egress window need to be?

What size does an egress window need to be?

IRC code minimums: 5.7 sq ft minimum net clear opening area, 20 inches minimum opening width, 24 inches minimum opening height, and sill no more than 44 inches above the finished floor. The 5.7 sq ft refers to the actual opening when the window is fully open (not the frame size). Casement windows are the most efficient because they open fully. Sliding and double-hung windows only open halfway, so they need to be larger frames to achieve the same clear opening. Check local codes — some jurisdictions require larger openings. Do I need an egress window in my basement?

Do I need an egress window in my basement?

You need an egress window in every basement bedroom (sleeping room). Without one, the room is not a legal bedroom and can't be counted as such in listings, appraisals, or tax assessments. Some jurisdictions also require egress in basement living areas (not just bedrooms). If your basement is unfinished and you're not using it for sleeping, egress windows aren't required but are still a good idea for safety and natural light. Adding egress windows and creating legal bedrooms can increase home value $10,000-$20,000+ per bedroom.

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Siding & Exterior

Egress Window Installation Guide: Cost, Code & Requirements

Lumberama Editorial Team, Basement Construction & Building Code Specialists Dec 5, 2025 9 min read

What Is an Egress Window?

Definition: An egress window is a window large enough for a person to escape through in an emergency and for firefighters to enter. Building codes require egress windows in every habitable room used for sleeping (bedrooms) that is below grade (basements) or above grade.

Why it matters: Safety: in a fire or emergency, occupants must be able to escape through the window. Without a proper egress window, a basement bedroom is a death trap. Code compliance: a basement bedroom without an egress window is not a legal bedroom. It can't be counted as a bedroom in the home's listing, appraisal, or tax assessment. Insurance: if someone is injured in a basement bedroom without code-compliant egress, the homeowner faces serious liability. Resale: adding egress windows and creating legal bedrooms increases home value ($10,000-$20,000+ per bedroom in many markets).

When required: Every basement bedroom (sleeping room). Any habitable room below the fourth story that is used for sleeping. Existing basements that are being finished or converted to include a bedroom. Some jurisdictions also require egress windows in basement living areas (not just bedrooms).

Code Requirements

IRC (International Residential Code) minimums: Minimum opening area: 5.7 square feet. Minimum opening width: 20 inches. Minimum opening height: 24 inches. Maximum sill height: 44 inches above the finished floor.

How to calculate: The 5.7 sq ft refers to the NET CLEAR OPENING — the actual opening when the window is fully open, not the size of the window frame or the rough opening. Example: a casement window that opens to 24 inches wide x 36 inches tall = 6 sq ft of clear opening (meets the 5.7 sq ft requirement). Note: different window styles have different clear opening ratios. Casement windows are the most efficient (they open fully). Sliding and double-hung windows only open halfway, so they need to be larger.

Window well requirements (for below-grade windows): Minimum width: 36 inches (measured from the window). Minimum area: 9 square feet. If the window well is deeper than 44 inches, a permanent ladder or steps are required. Ladder/steps must not interfere with the window opening. The window well must have drainage (gravel base with connection to the footing drain or a dedicated drain). A window well cover (grate) is optional but recommended. If used, it must be operable from inside without tools or keys.

Local codes: Some jurisdictions have stricter requirements than the IRC (larger opening, lower sill height, etc.). Always check with your local building department before ordering windows or starting work. A permit is required for egress window installation.

Cost

Per egress window (complete installation): Total installed cost: $2,000-$5,000 per window. This includes: concrete cutting (cutting through the foundation wall), excavation (digging the window well), window well installation (prefabricated steel or composite well), window (egress-compliant casement or slider), waterproofing and drainage, interior finishing (drywall, trim around the window), and backfill.

Cost breakdown: Concrete cutting: $500-$1,500 (depending on wall thickness and material — poured concrete vs block). Excavation and window well: $500-$1,500. Egress window unit: $300-$800. Installation (framing, flashing, sealing): $300-$600. Interior finishing: $200-$500. Window well cover: $50-$200. Permit: $100-$300.

Factors that increase cost: Thick foundation walls (10+ inches). Poured concrete (harder to cut than block). Deep window wells (more excavation). Landscaping that must be disturbed and restored. Utility lines near the window location. Rock or difficult soil conditions. Premium window brands or styles.

DIY vs professional: This is NOT a DIY project. It involves cutting through the foundation wall (structural), excavation near the foundation, waterproofing, and code compliance. Hire a professional egress window contractor. Look for companies that specialize in egress windows and basement waterproofing.

Installation Process

Step 1 — Planning and permits: Choose the window location (consider room layout, exterior landscaping, utility locations, and drainage). Size the window to meet or exceed code requirements. Apply for a building permit. Call 811 (dig line) to mark underground utilities.

Step 2 — Excavation: Dig the window well opening from the exterior. Excavate to the depth of the bottom of the window (plus gravel drainage base). The excavation extends 36+ inches from the foundation wall.

Step 3 — Concrete cutting: Cut the opening in the foundation wall. For poured concrete: use a concrete wall saw (specialized equipment). For block: remove blocks and install a lintel (beam) above the opening. The opening is sized to fit the window plus a rough opening frame. A structural lintel (steel angle iron or concrete lintel block) is installed above the opening to carry the load.

Step 4 — Window well installation: Install a prefabricated window well (galvanized steel, composite, or masonry). Secure the well to the foundation wall. Add 6-12 inches of gravel at the base for drainage. Connect the gravel bed to the footing drain (or install a dedicated drain to daylight or a sump).

Step 5 — Window installation: Set the window frame in the rough opening. Level, plumb, and square. Shim and fasten. Flash and seal the exterior (waterproofing membrane and sealant). Insulate around the window frame (spray foam).

Step 6 — Interior finishing: Frame the interior of the window opening (extend the opening to match the basement wall framing). Install drywall and trim. Paint.

Step 7 — Backfill and restore: Backfill around the window well. Restore landscaping, grading, and any hardscape that was disturbed. Install a window well cover (optional but recommended).

Timeline: Most egress window installations take 1-2 days per window.

Window Well Options

Prefabricated steel: The most common type. Corrugated galvanized steel. Durable and affordable ($100-$300). Available in standard sizes. Can rust over time (galvanized coating lasts 20-30+ years).

Composite/polymer: Won't rust or corrode. UV-resistant. More attractive appearance. Cost: $200-$500. Brands: Wellcraft, Rockwell. Some models include built-in steps.

Masonry (poured or block): Custom-built with poured concrete or block walls. The most durable and permanent. Can be finished with stone veneer for a high-end appearance. Cost: $500-$1,500+ (custom work).

Window well covers: Clear polycarbonate domes or flat covers. Keep out rain, snow, leaves, and debris. Allow light to enter. Must be operable from inside without tools (code requirement). Cost: $50-$200 per cover. Custom covers for oversized wells: $150-$400.

Landscaping around window wells: Grade the soil away from the window well (positive drainage). Use gravel, rock, or mulch around the well (not soil that can wash in). Planting: low-growing plants that won't block the window or fill the well. Avoid planting trees or large shrubs near the well. A well-designed window well with a cover, proper drainage, and attractive landscaping looks intentional and adds to curb appeal rather than detracting from it.