Moderate to Low. Requires expertise in excavation, concrete cutting, structural framing, waterproofing, and knowledge of building codes. Professional installation is highly recommended due to the critical nature of egress and structural integrity.
Installing egress windows, especially into existing foundation walls, often involves significant structural alterations, excavation, waterproofing, and compliance with multiple code sections, requiring professional planning and execution for safety and longevity in DuPage County's climate.
Project Guidelines & Rules
Permitting & Planning
2 Rules
Permit Acquisition
Prior to commencement of work, a building permit must be secured from your local municipality's building department. Plans must detail all aspects of the installation, including dimensions, structural changes, and window well design.
Pre-installation Inspection
Verify existing structural conditions, electrical, and plumbing lines that may be impacted. Consult with local building department if significant deviations from standard details are anticipated.
Emergency Escape & Rescue Opening Dimensions (2024 IRC)
6 Rules
Minimum Net Clear Opening Area
A minimum net clear opening of 5.7 square feet (0.530 m2) is required. For grade floor or basement openings, a minimum net clear opening of 5 square feet (0.465 m2) is permitted where the bottom of the clear opening is not more than 44 inches (1118 mm) above the finished floor. (IRC R310.2.1)
Minimum Net Clear Opening Height
A minimum net clear opening height of 24 inches (610 mm) is required. (IRC R310.2.2)
Minimum Net Clear Opening Width
A minimum net clear opening width of 20 inches (508 mm) is required. (IRC R310.2.3)
Maximum Sill Height
The bottom of the clear opening shall be not more than 44 inches (1118 mm) above the finished floor. (IRC R310.2.4)
Operability
Emergency escape and rescue openings shall be operational from the inside of the room without the use of keys, tools, or special knowledge. (IRC R310.2.6)
Glazing
Safety glazing is required in hazardous locations as defined, including windows that are near walking surfaces or doors. (IRC R308.4)
Window Well Requirements (2024 IRC)
3 Rules
Horizontal Dimensions
Window wells shall have a minimum horizontal area of 9 square feet (0.836 m2), with a minimum horizontal projection and width of 36 inches (914 mm). (IRC R310.2.5.1)
Ladders or Steps
Where the window well depth exceeds 44 inches (1118 mm), a permanently affixed ladder or steps shall be provided. The ladder or steps shall not encroach into the required dimensions of the window well by more than 6 inches (152 mm) and shall have a minimum inside width of 12 inches (305 mm). (IRC R310.2.5.1)
Drainage
Window wells shall be drained by a means approved by the local building department. Options include connection to a stormwater management system, foundation drainage, or a drywell designed for the soil conditions. (IRC R310.2.5.2)
Structural Integrity & Framing (2024 IRC)
3 Rules
Header Sizing
All new or modified openings in bearing walls shall be properly headed to support structural loads. Headers shall be sized according to IRC R602.7 or engineered drawings if beyond prescriptive tables. Supporting jack studs and cripples are required. (IRC R602.7)
Foundation Wall Alterations
Cutting existing concrete or masonry foundation walls requires careful consideration of structural integrity. Reinforcing steel (rebar) continuity and proper patching/sealing with non-shrink grout or similar approved materials are essential. Engineering review may be required. (IRC R404)
Anchorage
New framing elements shall be properly anchored to existing structures and foundations. (IRC R403, R602)
Excavation, Foundation & Drainage (2024 IRC & DuPage County Climate)
4 Rules
Frost Protection for Window Wells
Any structural footing for a window well system (if applicable) must extend to a minimum frost depth of 42 inches (1067 mm) below grade in DuPage County. (IRC R403.1.4.1, DuPage County Amendment)
Waterproofing and Dampproofing
Foundation walls, including those modified for egress windows, shall be dampproofed or waterproofed to prevent moisture intrusion. (IRC R406)
Exterior Flashing
Flashing shall be installed at all exterior wall openings to prevent water penetration. This includes sill flashing, jamb flashing, and head flashing integrated into the weather-resistive barrier. (IRC R703.8)
Grading
The finished grade shall slope away from the foundation a minimum of 6 inches (152 mm) within the first 10 feet (3048 mm). (IRC R401.3)
Energy Efficiency & Weatherization (2024 IRC)
2 Rules
Window Performance
Replacement windows and new windows must meet the current energy efficiency requirements for Fenestration U-factor and Solar Heat Gain Coefficient (SHGC) as specified in the IRC for Climate Zone 5 (DuPage County). (IRC N1102.5, Table N1102.1.2)
Air Sealing & Insulation
All joints, seams, and penetrations in the building envelope around the new window opening must be thoroughly air-sealed and insulated to maintain the thermal performance of the wall assembly. (IRC N1102.4)
Ancillary Code Considerations (2023 NEC & IL Plumbing Code)
2 Rules
Electrical System Protection
Any existing electrical wiring, junction boxes, or devices encountered during the wall modification must be protected from damage, relocated if necessary, and reinstalled in compliance with the 2023 National Electrical Code (NEC). Ensure proper wiring methods, box fill, and protection from physical damage. (2023 NEC 300.4, 314.16)
Plumbing System Protection
Any existing plumbing supply lines, drain lines, or vent pipes disturbed during the project must be protected, properly rerouted, and reconnected in accordance with the Illinois Plumbing Code. Ensure proper support, grading for drainage, and leak-free connections. (Illinois Plumbing Code Sections 890.300, 890.330, 890.410)
