Published 2026-03-20 · Madison Foundation Pros
Wisconsin Egress Window Code: What's Required for a Below-Grade Bedroom
Quick answer: Wisconsin SPS 321.03(2) requires every below-grade sleeping room to have an emergency escape and rescue opening. The four numbers do not bend: 5.7 square feet net clear opening, 24-inch minimum height, 20-inch minimum width, 44-inch maximum sill height above the finished floor. The window well needs at least 9 square feet of floor area and a 36-inch projection from the wall. Permit fees in the Madison metro run $75 to $250, depending on jurisdiction.
The four numbers, and why each one exists
Wisconsin SPS 321.03(2) reads like a math problem because that is what fire-rescue training calls for. Each measurement traces back to a specific scenario the code is trying to prevent. The 5.7 square feet of net clear opening matches the silhouette of a firefighter wearing full SCBA gear, so they can enter the room to pull a child out. The 24-inch minimum opening height keeps a tall adult from getting wedged at the shoulders on the way out. The 20-inch minimum opening width works for the same reason at the hips. And the 44-inch maximum sill height keeps the opening within reach of a child standing on the floor, which is why a higher sill always requires a permanent step or platform.
None of those numbers are guidance. They are the dimensions the inspector measures with a tape, and the inspection passes or fails on the actual reading from the open window. A spec sheet that claims compliance does not substitute for the measurement.
Where the rule lives, and who enforces it
The Wisconsin Department of Safety and Professional Services publishes SPS 321 under the Uniform Dwelling Code. The rule is statewide, which means a basement bedroom in Madison, Stoughton, Cottage Grove, or anywhere else in Wisconsin gets the same measurements. Enforcement runs through the local building inspector, and Dane County jurisdictions delegate the inspection to municipal staff in Madison, Middleton, Verona, Sun Prairie, Fitchburg, Stoughton, McFarland, Monona, Waunakee, and Cottage Grove. A few smaller townships still run their inspections through Dane County directly. We confirm the jurisdiction during the free measurement visit, because the permit application goes to whichever office holds authority.
What "net clear opening" actually means
The phrase trips up more contractors than any other line in the code. Net clear opening is the area you can pass through with the window fully open, measured between the sash and the frame. It is not the rough opening you cut in the concrete, and it is not the spec-sheet area calculated with the sash fully removed. A casement window that swings 90 degrees gives you nearly the full rough-opening area as net clear. A double-hung window only gives you half the opening at most. A slider gives you about half. That math matters because a casement is usually the right window for a basement egress, even though it costs more than a slider of the same outside dimensions.
Two casement models we install most often in the Madison metro: the Pella 2052 and the Andersen 400-Series CW235. Both clear 5.9 to 6.1 square feet of net opening at the standard residential mounting position. We have also installed Marvin Essential casements where the homeowner wanted a wood interior. Slider-style egress units from any manufacturer rarely meet the rule in the typical Madison basement-rough-opening size, so they show up on basement remodels less often than the catalog photos would suggest.
The window well rules, point by point
The well is the second half of the code requirement, and the inspector reads its measurements as carefully as the window itself.
- 9 square feet of horizontal floor area at the base of the well, measured inside the well walls. A standard 36-by-36-inch well delivers exactly 9 square feet, which is the floor of the spec.
- 36-inch minimum projection from the foundation wall. A well that hugs the wall at 30 inches will fail even if its floor area math works.
- Permanent ladder or steps in any well deeper than 44 inches from the lip to the well floor. Ladders cannot project more than 6 inches into the well opening, which means most Madison installs use a wall-mounted galvanized ladder rather than a free-standing one.
- Drainage at the base. Standing water in a window well becomes a basement leak the first hard rain. Inspectors increasingly want a gravel layer to the footing drain or a sealed connection to the sump system.
Bilco and Rockwell make the two galvanized-steel wells we install most often in Dane County. The Bilco model with the integrated ladder runs about $700 retail, sized for an 8-inch poured wall. The Rockwell precast option costs less but adds installation labor because of the weight.
Permit fees and timing by Madison-area jurisdiction
The fee varies by city and by what gets bundled with the inspection. Five years of permits across our service area put the typical numbers in this range:
| City | Permit fee | Plan review time |
|---|---|---|
| Madison | $130 to $190 | 5 to 10 business days |
| Middleton | $120 to $170 | 5 to 10 business days |
| Verona | $95 to $130 | 5 to 7 business days |
| Sun Prairie | $110 to $160 | 5 to 10 business days |
| Fitchburg | $120 to $170 | 7 to 10 business days |
| Waunakee | $150 to $200 | 5 to 10 business days |
| Stoughton | $100 to $140 | 5 to 7 business days |
| McFarland | $90 to $130 | 5 to 7 business days |
| Monona | $110 to $150 | 5 to 10 business days |
| Cottage Grove | $90 to $140 | 5 to 7 business days |
Every permit triggers two inspections. The rough-in inspection happens after the wall is cut and the lintel is set but before the window goes in. The final inspection happens after the well is set and the trim is complete. We schedule both with the inspector's office and meet them on site so the homeowner does not have to take time off work.
Three real Madison-area projects
A 1962 ranch in the Atwood neighborhood needed an egress in a basement bedroom that had been finished without a permit a decade earlier. The owners had drywalled around the existing 20-by-14-inch window, which delivered roughly 1.9 square feet of net clear, well below the rule. We cut a new 36-by-48-inch opening, set a Pella 2052 casement (6.0 square feet net clear), installed a Bilco well with an integrated ladder, and pulled the Madison permit. Total: $3,800, two days on site, plus the inspector visit a week later.
A Sun Prairie home in Bristol Ridge built in 2003 had a code-compliant basement window that the owners wanted to enlarge for a guest bedroom they were adding. The existing window cleared 4.8 square feet of net opening, short of the 5.7 mandate. We enlarged the rough opening by 8 inches in height (no structural rework needed because the wall above was non-load-bearing), set an Andersen 400-Series CW235, and reused the existing well with a slight modification. Total: $2,900, one day on site. The lower cost reflects the existing well and the simpler cut.
A 1908 home near Tenney-Lapham took the most engineering. The rubble-stone limestone wall was load-bearing, and cutting the opening required a stamped engineering plan, a steel lintel, and a rebuild around the new window with hand-mixed lime mortar. Our P.E. partner reviewed the cut location relative to the joists above and specified a 4-by-6 steel angle for the lintel. Total: $7,200 with the engineering report, three days on site spread across two visits. The basement gained 380 square feet of code-compliant livable space, which the buyer's market in 2024 valued at roughly $58,000 against the city's $150-per-foot recent comp average.
What happens when the rule is ignored
Three failure modes show up at the closing table when a basement bedroom does not have a compliant egress. The first is the buyer's inspector flagging the room and the deal pausing while the seller scrambles to add the window. The second is the appraiser refusing to count the room as a bedroom for square-footage purposes, which can drop the appraisal by $30,000 to $80,000 against a buyer's contracted price. The third, less common but more serious, is the city issuing a stop-use order on the room when a permit search during the sale surfaces the unpermitted finish work. The 2024 Madison-market data put roughly 4 percent of basement-finished home sales into deal-pause territory because of egress noncompliance.
What an honest egress contractor includes in the quote
A real quote breaks out four items and names a number for each.
- The window manufacturer and model number, with the net clear opening listed against the SPS 321.03(2) minimum.
- The window well manufacturer, size, depth, and whether a permanent ladder is included.
- The permit fee as a separate line, with the jurisdiction named (Madison, Verona, Waunakee, whichever applies).
- The structural detail (steel lintel sizing or a note that the cut is in a non-load-bearing wall), with the engineering stamp called out if required.
If any of those four items reads as "as required" or "TBD," ask the contractor to fill in the number before you sign. A real quote on this scope can be specific because the code is specific.
Frequently asked
What is the Wisconsin code section for basement bedroom egress windows?
Wisconsin Uniform Dwelling Code SPS 321.03(2) controls emergency escape and rescue openings in residential dwellings. The same numbers appear in the International Residential Code (IRC) Section R310 that Wisconsin adopted with state-specific modifications. The Wisconsin Department of Safety and Professional Services publishes the rule online, and your Dane County inspector will reference it on the permit card. If a contractor cannot quote the SPS section number from memory, that is a reason to keep looking.
Does every basement bedroom need an egress window in Wisconsin?
Yes, if the room is used as a sleeping room and the floor sits below grade. The code does not bend on this point. A basement office, a basement gym, or a basement laundry room does not require an egress. The instant a bed and a closet go into the room and a buyer's inspector sees it as a bedroom, the rule applies. Finishing a basement room as a bedroom without the egress is the single most common reason a Madison-area home sale falls apart in due diligence.
What are the four numbers the inspector will measure?
Net clear opening of at least 5.7 square feet. Minimum opening height of 24 inches. Minimum opening width of 20 inches. Maximum sill height of 44 inches above the finished basement floor. The inspector uses a tape measure on the open window, not the spec sheet. A casement that lists 6.0 square feet in the catalog but only delivers 5.4 square feet of net clear when the sash hits the limit stop will fail.
What does the window well have to look like?
Minimum 9 square feet of horizontal floor area at the base of the well. Minimum projection of 36 inches from the foundation wall. If the well is deeper than 44 inches from the lip to the floor of the well, a permanent ladder or steps are required. The ladder rungs cannot project more than 6 inches into the well opening. Most Madison-area inspectors also want to see drainage at the base of the well, either a gravel layer to the footing drain or a connection to the sump system.
How long does the Madison permit process take for an egress window?
Five to ten business days for the permit itself once we submit the application, plus the inspection window after the cut. Madison runs $130 to $190 for the permit. Verona is closer to $100. Waunakee tends to land around $175. Cottage Grove and McFarland fall in the $90 to $140 range. We pull the permit, schedule both required inspections (rough-in after the cut, final after the window is set), and hand the signed permit card to you at closeout.
Can a window meet the code without a window well?
Only if the sill of the window sits at or above grade on at least one face of the foundation, which is rare in a Madison basement. Most homes here sit four to seven feet below grade at the basement floor, which puts the sill below grade and forces a well. The exception is a daylight basement where the lot slope drops away from one foundation wall, which we see most often in Verona's Hawks Landing and on the south-facing slopes of Middleton's Bishops Bay.
Ready to add a code-compliant egress?
Call (608) 407-7510 for a free in-home measurement and a written quote within 48 hours. See the egress window installation service page for the wall-cut process, the full Madison foundation cost guide for pricing across every service we run, our Madison service area page for the broader Dane County context, and our companion article on egress window installation costs for the full pricing breakdown.
Last updated: 2026-03-20.