Low - Requires specialized equipment, technical expertise in excavation, concrete forming and pouring, masonry, waterproofing, and electrical work. Strict adherence to structural, safety, and drainage codes is paramount. Professional general contractors and trades are strongly recommended to ensure code compliance and long-term durability.
Involves significant excavation, structural concrete and masonry work, extensive waterproofing and drainage systems, multiple safety requirements (egress, handrails, guards), and electrical installation for lighting, necessitating careful design, execution, and coordination across multiple building disciplines to meet DuPage County and state building codes.
Project Guidelines & Rules
General & Administrative Requirements
3 Rules
Permit Application
A building permit is required from your local building department prior to commencement of any construction activities. Submittal documents typically include a detailed site plan, construction drawings, and engineering calculations where applicable.
Inspections
Required inspections typically include footing, foundation/rebar, damp-proofing/waterproofing and drain tile, rough framing (if applicable), rough electrical, and final inspections. Consult your local building department for specific inspection schedules.
Site Plan
A detailed site plan indicating proposed stairwell location, dimensions, drainage patterns, and setbacks from property lines and existing structures must be submitted for review.
Structural & Foundation Requirements
5 Rules
Footing Depth (Frost Protection)
All footings for exterior basement stairwell walls shall extend a minimum of 42 inches below adjacent finished grade to protect against frost heave, consistent with DuPage County climate standards. (2024 IRC R403.1.4)
Footing Dimensions
Concrete footings shall be a minimum of 6 inches thick and extend at least 12 inches beyond the face of the wall on both sides, or as specified by engineered design. (2024 IRC R403.1.1)
Foundation Wall Construction
Exterior basement stairwell walls that retain earth shall be designed to resist lateral soil pressures and hydrostatic pressures, and shall be a minimum of 8 inches nominal thickness for concrete or masonry, reinforced as per IRC Section R404. (2024 IRC R404.1)
Reinforcement
Reinforcement for concrete walls shall conform to ACI 318 or as specified by engineered design, with rebar placement per approved plans. (2024 IRC R404.1.2)
Concrete Compressive Strength
Concrete used for footings, walls, and stairs shall have a minimum compressive strength of 3000 psi at 28 days. (2024 IRC R402.2)
Egress & Safety (Stairways, Handrails, Guards)
10 Rules
Stairway Width
Stairways shall not be less than 36 inches in clear width at all points above the permitted handrail height and below the required headroom height. (2024 IRC R311.7.1)
Headroom
The minimum headroom in all parts of the stairway shall not be less than 6 feet 8 inches measured vertically from the sloped line adjoining the tread nosing or from the landing surface. (2024 IRC R311.7.2)
Riser Height
The maximum riser height shall be 7 3/4 inches. The greatest riser height within any flight of stairs shall not exceed the smallest by more than 3/8 inch. (2024 IRC R311.7.5.1)
Tread Depth
The minimum tread depth shall be 10 inches. The greatest tread depth within any flight of stairs shall not exceed the smallest by more than 3/8 inch. (2024 IRC R311.7.5.2)
Landings
A landing shall be provided at the top and bottom of each stairway. The minimum dimension of landings in the direction of travel shall be not less than 36 inches. (2024 IRC R311.7.6)
Handrails
Handrails shall be provided on at least one side of stairways with four or more risers. Handrails shall be continuous for the full length of the flight, from a point directly above the top riser to a point directly above the lowest riser. (2024 IRC R311.7.8)
Handrail Height
Handrail height, measured vertically from the sloped plane adjoining the tread nosings or finished surface of the landing, shall be not less than 34 inches and not more than 38 inches. (2024 IRC R311.7.8.1)
Guards
Open sides of stairways, landings, and the well enclosure that are more than 30 inches above grade shall be protected by guards. Guards shall be a minimum of 36 inches in height. (2024 IRC R312.1.1, R312.1.2)
Guard Openings
Required guards shall not have openings through which a 4-inch diameter sphere can pass. (2024 IRC R312.1.3)
Stair Material
Exterior stairs and landings shall be constructed of approved weather-resistant materials (e.g., concrete, treated lumber, composite). (2024 IRC R317.1)
Drainage & Waterproofing
5 Rules
Exterior Grading
The finished grade around the exterior stairwell shall be sloped away from the foundation with a minimum slope of 6 inches in the first 10 feet to divert surface water. (2024 IRC R401.3)
Subsurface Drainage (Drain Tile)
A drainage system consisting of a drain tile or perforated pipe shall be installed at or below the level of the footing around the perimeter of the stairwell excavation and discharge to an approved location (e.g., sump pit with pump, storm sewer). (2024 IRC R405.1, R405.2)
Waterproofing/Damp-proofing
Foundation walls, including those of the stairwell, that retain earth and enclose habitable or usable spaces below grade shall be damp-proofed or waterproofed from the top of the footing to the finished grade using approved methods and materials. (2024 IRC R406.1, R406.2)
Sump Pump Discharge
Any sump pump discharge from foundation drainage systems shall be directed to an approved point of discharge, ensuring it does not create a nuisance, ice hazard on public ways, or discharge into a sanitary sewer. (Illinois Plumbing Code 890.150 - General Principles)
Backfill
Backfill shall be placed in a manner that prevents damage to the foundation and waterproofing materials. Granular fill may be required against walls to facilitate drainage. (2024 IRC R408.1)
Electrical Requirements
4 Rules
Stairway Illumination
All exterior stairways, including exterior basement stairwells, shall be provided with illumination at the walking surface. Such illumination shall be controlled by a wall switch located at each floor level and landing where a door provides access to the stairway. (2024 IRC R303.8.1, R303.8.2)
GFCI Protection
All 120-volt, single-phase, 15- and 20-ampere receptacles installed outdoors, or in a basement if a sump pump receptacle is present, shall have ground-fault circuit-interrupter protection for personnel. (2023 NEC 210.8(A)(3), 210.8(A)(5))
Underground Wiring
Wiring installed underground shall comply with NEC 300.5. All conductors below grade shall be suitable for wet locations and installed at appropriate burial depths. (2023 NEC 300.5, 310.10(C))
Wet Location Equipment
Electrical equipment and wiring installed in wet locations (e.g., exterior fixtures, switches) shall be listed and installed for wet locations. (2023 NEC 406.9(A))
