Cutting and enlarging foundation openings
When the existing basement window is too small, the wall itself has to change. Here's how a contractor makes the opening bigger safely.
A typical old basement window might be a couple of feet wide and barely a foot tall. To reach code size, the opening usually has to grow down toward the floor and often sideways too. That means cutting the foundation wall, which is structural work that has to be planned before the saw comes out.
Poured concrete or block?
Poured walls are cut with a large diamond saw, often from both sides, and the cut piece is broken out and hauled away. Block walls are cut too, but the cut edges of the hollow cores have to be filled or capped so the sides of the opening are solid. Either way, the top of the opening needs to carry the weight of the house above, so a header or lintel is often added.
What does St. Cloud want to see?
The city's window handout says changing a window's size or adding an opening needs a floor plan showing the new window, nearby doors, the header size and the loads on it. Sharing that with the contractor early helps the permit move along. Expect the inspector to look at the framing or header before the opening is closed up.
Dust, water and mess
- Wet cutting keeps dust down but brings water into the work area
- Furniture and finished spaces nearby should be moved or covered
- Old windows in homes built before 1978 can have lead paint, and the city notes contractors on those homes need EPA lead firm certification
- Utility lines, gas meters and dryer vents near the wall affect where the cut can go
What affects the price?
- Wall type and thickness
- How much the opening grows
- Header or lintel requirements
- Inside finishes that have to be removed and patched
The contractor prices the job after seeing the wall, the yard and the room. We don't quote prices, and anything said over the phone before a site visit is only a ballpark.
Where we connect you with help
Common questions
Is it safe to cut a bigger hole in my foundation?
When it's planned and supported properly, yes. That's why the opening usually gets a header and why the city reviews the plan before the permit is issued.
Can I keep my old window well?
Usually not. A code-size window needs a well at least 36 inches wide and 36 inches out from the wall, which most original wells don't reach.
Related services
- Basement egress window installation
- Window wells and ladders
- Window well covers
- Basement bedroom code compliance
More background: St. Cloud egress window guide.
Turning a basement room into a real bedroom?
Call and a local egress contractor will look at the wall, the yard and the permit with you.