Wichita's 24-Inch Frost Depth: What Winter Really Means for an Egress Window Dig

September 18, 2026

Most egress window content on the internet is written for the upper Midwest, where the honest advice is that excavation season runs April to November and a January dig is a fantasy. Wichita is not that market, and the difference is written into our own code.

Wichita’s frost depth is 24 inches. Not a rule of thumb, not a regional average. It is in the adoption ordinance for the 2018 International Residential Code as the Wichita/Sedgwick County Unified Building and Trade Code amends it: R403.1.4 as amended requires all exterior footings at least 24 inches below undisturbed ground, and R403.1.4.1 as amended reads that footings shall not bear on frozen soil, and that frost depth in Wichita is 24 inches. Haysville’s own ordinance carries the same language for Haysville and Sedgwick County.

Sioux Falls builds to 42 inches. Minneapolis works deeper still. We work to 24, and the practical consequences run through the whole job.

What 24 inches changes, and what it does not

It does not set the depth of your hole. This is the most common misunderstanding, so it is worth being blunt. Frost depth governs where a footing can bear. It has nothing to do with how deep an egress excavation goes. The sill of the new window sets that, and on a full-height Wichita basement the sill sits several feet below grade. Then the bottom of the well goes below the sill, and under the well goes the 12 inches of washed gravel or crushed rock the local code requires where there is no foundation drainage system to tie into. Add working room and the dig on a typical full install runs 5 to 6 feet deep. You are past the frost line before you are a third of the way down.

It does change how often the top of the hole is frozen. Frozen ground is slow and unpleasant to excavate, and more importantly it is a nightmare to backfill properly, because frozen clumps of clay do not compact. They sit there as voids until they thaw, and then the backfill settles, the grade reverses toward the house, and the well you just paid for starts collecting water. Backfilling into a frozen trench is how you get a callback in April.

It changes the arithmetic on whether winter is worth waiting out. In a 42-inch frost market, that top layer is the whole job for months. Here, the frozen band is shallow and episodic.

What a Wichita winter actually looks like

The normals tell the story better than anything anybody feels in February. NOAA’s 1991 to 2020 figures for Wichita Eisenhower National Airport:

The normal daily high in January is 43.9 degrees. Above freezing, in the coldest month. Annual snowfall normal is 12.7 inches, and the most in any single month is February’s 3.6.

That is a climate where hard freezes arrive as events, sit for a few days to a week, and let go. It is not a climate where the ground locks up in November and stays that way. Which is why the correct answer to “can you do this in January” in Wichita is a forecast question, not a calendar question.

The real scheduling constraints, in order

Weather is rarely the thing that actually delays an egress job here. These three are.

1. The permit

Cutting a foundation is structural work and it needs a building permit. Inside Wichita and in unincorporated Sedgwick County that is the Metropolitan Area Building and Construction Department, which also licenses the contractors, since Kansas issues no statewide contractor licence. MABCD prices a residential remodel off its Table B by valuation, which puts an egress job at roughly $92 to $125, itemized on our quote at cost.

The suburbs each run their own desk. Derby, Haysville, Park City and Valley Center issue their own permits and do their own inspections; Valley Center requires a city contractor licence as well. Andover adopted the Wichita/Sedgwick County code by its own ordinance in 2025 and takes an MABCD licence plus a certificate of insurance naming the city. Maize and Goddard route plan review and inspections through MABCD. Review time varies by desk and by season, and it is the single most common reason a start date moves. The code page has the table of which town uses which.

2. The utility locate

Kansas law is specific and it is not waivable. Under K.S.A. 66-1804 an excavator has to serve notice of intent to excavate at least two full working days, and not more than 20 calendar days, before the scheduled start date, and the notice stays valid for 20 calendar days after that start date. That notice carries the excavator’s details, the start date, the type of excavation and the specific location.

In plain terms: the locate ticket is a small, fixed, legally required piece of lead time on every dig, and it does not care what the weather is doing. A contractor who offers to dig tomorrow has either already called it in or is not calling it in.

3. A workable weather window

Then the forecast. What we are looking for is not warmth, it is a few days without the ground hard at the surface and without rain on the way, so the hole can be opened, the wall cut, the well set and the backfill compacted in lifts rather than dumped in frozen.

The season we actually recommend

Fall is the best time to do this work in Wichita. The ground is dry, the spring rain is months behind, the permit desks are past the summer rush, and the inside of the job, framing and drywall in a finished basement bedroom, happens over the winter when you are indoors anyway.

Winter is fine, with flexibility. If you are on a closing timeline or a buyer’s inspection has flagged the room, we work in winter and the price does not change. Bring patience for one or two schedule slips around cold snaps.

Late spring is the stretch we steer people away from. Not for cold, for water. NOAA’s normals put 5.17 inches on the city in May and 4.93 in June, 38 percent of the annual total across April through June, onto silty clay that NRCS classes Hydrologic Group D for its very slow infiltration. A 6-foot hole in that clay during the wettest eight weeks of the year fills as fast as you dig it, the spoil turns to something you cannot backfill with, and the lawn takes the worst of it. If your well flooded in May, the right answer is usually to get measured in May and dig in September. Our post on why Wichita wells flood in May explains what is happening underneath.

Summer works. July and August are hot and dry and the ground digs well. The only thing to say for it is that the crews are busy.

What runs in any month

Interior work does not care about the ground at all. A basement window replacement in an existing opening, at $400 to $1,100 per window, is a January job like any other, and under the amended R105.2 a like-for-like swap that does not cut or alter a structural member is usually exempt from permit, with the caveat that a smaller unit may not reduce a required escape and rescue opening.

Well covers go on year round at $150 to $600, and a cover is the best winter purchase in this trade: it keeps snowmelt and February’s 3.6 inches of snow out of a well that is going to spend March draining.

Measures and quotes happen year round, and if you are planning a fall dig, a winter measure means the permit is filed and the window is ordered long before the ground is ready.

The honest summary

Wichita’s shallow frost line is a genuine local advantage and most egress content will not tell you about it, because most egress content was written for Minnesota. The dig season here is most of the year. What limits your start date is the permit desk, the two-working-day locate notice, and a forecast, in that order, and only one of those three is about winter at all.

Prices for everything above are on the pricing page, the egress cost calculator prices your specific job, and we work across Wichita, Derby, Haysville, Maize and the rest of Sedgwick County.