Basement Windows

Question Icon
Posted by: from Mississauga
3/7/2010 at 10:23:23 PM

We would like to add a den and extra bedroom into a partially finished basement of our 30 year old bungalow. There are currently two very small windows that are covered by our deck. We would like to install 2-3 extra windows (one would have to meet fire codes for basement bedrooms). Since they will be cutting into our foundation I assume we will need a permit.

What would the approximate cost be for installing basement windows? Anything else we should be aware of since cutting into foundation is involved?

User Icon
Mike from Barnworks in Port Hope
Date/Time8/4/2010 at 9:10:02 PM

For installing a bigger window in a foundation, I know I charge $300 plus the price of the window, and yes you do need a permit.

User Icon
Date/Time1/25/2011 at 8:30:06 AM

Hi First off you need to get a building permit

Depending on the depth of the foundation

if the new window will remain above grade, we charge 400.00 this is called a total prepare block modification.

if the new window is below grade at all then you need window well installed approx 250.00 also drainage if the tile exists as with most foundations approx another 400.00 to excavate and hook up tile...


of course

User Icon
Date/Time2/7/2011 at 12:21:02 PM

Hi Sandy,

I hope this somewhat applies to Ontario Building Code but here in Alberta when I want to cut in windows to the side of a house I need to get the side elevation drawings as well as the real property report and take that into the permit office along with my drawing of proposed windows. Your drawings can be simple, done on graph paper to scale so nothing to worry about there. Make sure to include at each new window thecation; the actual opening size dimensions of the window. Egress code allows for a sliding window in basement bedrooms out here and the dimensions of the opened part of the window can be a minimum of 3.8 sq ft of room to escape

Based on how close you are to your neighbors house and how many windows you currently have will relate to what is acceptable. A quick example is neighbouring properties where the homes are 4 feet from the property line are allowed to have a maximum of 7 percent of the homes side exterior square footage be windows. Any part of the window beneath grade (underground) does not apply to the total

Call 311 and ask for the head building inspector in your area and they are usually happy to fill you in on what is code and how to go about it in your area. You can do it without permits and cross your fingers no one complains but realistically for a small amount of work and very little extra cost you can have everything done legally and never have problems come resale. Well worth it if you ask me

Hope this helps, good luck with the city

Jeff Payne

Oslo Design


Search the TrustedPros directory and discover the best contractors in your area.

Find your home service pro
Great renovations start with a great contractor.

Since 2004, TrustedPros has been helping homeowners find the right contractor for their home improvements and repairs.

Post Your Project

Within hours you'll be comparing offers from top-rated professionals. It's free to post and you're under no obligation to hire.

Trustedpros Inc. does not warrant the accuracy, completeness, safety, legality or usefulness of any Content, or Whether Content is Current and up-to-date, and TrustedPros Inc. Shall have no liability whatsoever with respect to your use or reliance upon any content or for content being removed or otherwise ceasing to be available. Please refer to the terms and conditions of use of this websites for more details.

Get Free Estimates

Post your project and compare offers from top-rated pros.