An egress window is a basement window big enough for a person to climb out during a fire, and Iowa code requires one in every basement bedroom. Most older Mason City basements do not have one. The small hopper windows in a 1950s foundation are too tiny and sit too high on the wall. If you want to finish your basement or add a bedroom down there, sort this out first.
TL/DR
- An egress window gives you a legal way out of the basement in a fire. Iowa follows the IRC: 5.7 square feet of clear opening, 20 inches wide, 24 inches tall, still no higher than 44 inches.
- Every basement bedroom needs one. Most finished basements need one too. The job means cutting the foundation, so it is not a weekend project.
- Most basement egress projects run $3,000 to $6,000 installed. The Window Source of Mason City measures your basement for free.
What is an egress window?
An egress window is a window sized so a person can get out and a firefighter can get in wearing full gear. Egress just means exit.
A regular basement window is there for light and air. An egress window is a door you happen to look through. That is why the size rules are strict. A brand new window that is too small will still fail inspection.
What are the egress window requirements in Iowa?
Iowa follows the International Residential Code, or IRC, which calls for 5.7 square feet of net clear opening, at least 20 inches wide and 24 inches tall, with the sill no more than 44 inches off the floor.
Net clear opening means the actual hole you crawl through when the window is all the way open. It is not the size of the frame. A lot of homeowners get tripped up there.
| Requirement | Minimum |
| Net clear opening | 5.7 sq ft (5.0 sq ft at ground level) |
| Opening width | 20 inches |
| Opening height | 24 inches |
| Sill height above floor | No more than 44 inches |
| Window well size | 9 sq ft, at least 36 inches out from the wall |
| Window well ladder | Needed if the well is deeper than 44 inches |
The window also has to open from inside without a key or a tool. Check the current rules with the City of Mason City building department before you order anything, since local rules change.
When does a basement need an egress window?
Any basement bedroom needs one, and most finished basements do too. This comes up when you:
- Add a bedroom in the basement
- Finish the basement into living space
- Turn the basement into a rental or in-law suite
- Sell the house and the inspector flags the basement bedroom
- Pull a permit for any basement work
That last one catches people off guard. Once you pull a permit, the inspector looks at the whole space. A bedroom with no way out gets called out every time.
What kind of window works best for basement egress?
Casement windows work best in Iowa basements because they swing all the way open and give you the full 5.7 square feet from a smaller frame.
- Casement: Cranks open like a door. Biggest opening for the smallest hole in the wall. The usual pick.
- Sliding: Slides sideways. Only half of it ever opens, so you need a much wider cut.
- Double-hung: Slides up and down. Same issue. Half opens, so the unit has to be large.
- Hopper: Tips open from the top. Fits some basements but takes up floor space.
Go with vinyl frames, double-pane glass, and a Low-E coating. Basements run cold and damp, and an old single-pane window down there drips all winter.
How does the installation work?
A basement egress install means cutting the foundation, setting the window, digging the well, and adding drainage. Here is the order.
Step 1: Check the wall and mark the opening
We look at where the floor joists land, where the pipes and wires run, and how deep the frost line sits. Then we mark the cut. Nothing gets cut until the layout is right.
Step 2: Cut the foundation
A concrete saw opens the wall. On a poured concrete wall, we add a header above and support on the sides so the foundation still carries its weight. This is the part that makes it a pro job.
Step 3: Set the window and seal it
The window goes in level and square. We flash the opening, seal the top and both sides, and leave the bottom open so water can drain. Same rules as any other window.
Step 4: Dig and set the window well
The well needs 9 square feet and has to stick out at least 36 inches from the wall. Steel and composite wells both work. A well deeper than 44 inches needs a built-in ladder.
Step 5: Handle the water
We put gravel in the bottom of the well and tie it into your drain tile or a dry well. Skip this in Iowa and the well fills with meltwater every spring.
What does a basement egress window cost in Mason City?
Most basement egress projects run $3,000 to $6,000 installed, and the concrete work costs more than the window itself.
What moves the price:
- Poured concrete walls cost more to cut than block foundations
- Deep basements need bigger wells and a ladder
- A tight side yard makes digging slower
- Existing drain tile saves money, a new dry well adds to it
- A wider opening needs more support above it
Get the quote in writing. Make sure it names the well, the drainage, and the permit. Cheap bids leave those out, and that is where the extra cost shows up later.
Why homeowners here call The Window Source of Mason City
We handle the window side of basement egress work, and we tell you straight what your basement needs before you spend a dollar.
- Locally owned and run: We live here, so we know what Iowa winters and spring thaw do to a basement wall.
- A rating from the BBB: No runaround on warranty claims or callbacks.
- Readers’ Choice winner: Voted Best Window Company and Best Siding Company by people in this area.
- Limited lifetime warranty: Every project carries it, egress windows included.
- Financing available: Ask about the options before you rule the job out on price.
- Free in-home measure: We size the opening and tell you what will pass inspection.
- Serving North-Central Iowa: Mason City, Clear Lake, Garner, Algona, Charles City, and the towns around them.
Get a free estimate
A basement bedroom without an egress window will not pass inspection. Get that part settled before you frame a single wall. Reach out to The Window Source of Mason City and we will come measure your basement for free. You get a straight answer on what your basement needs and what it costs. No pressure after that.
FAQs
How big does an egress window have to be?
At least 5.7 square feet of clear opening, 20 inches wide and 24 inches tall, with the sill no more than 44 inches above the basement floor.
Can I put an egress window in a block foundation?
Yes. Block walls cut cleaner than poured concrete and usually cost less. The opening still needs proper support above it.
How long does the install take?
Most jobs finish in one to three days. Cutting takes a day, and the window well and drainage take another.
Does an egress window add value to my home?
It does. It makes a basement bedroom legal, and that bedroom counts when you list the house.
Do I need a window well ladder?
Only if the well runs deeper than 44 inches. Plenty of Mason City basements hit that mark, so ask before you order.
Will an egress window make my basement colder?
No, as long as you use double-pane glass with a Low-E coating. New basement windows hold heat better than the old single-pane ones they replace.