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Everything You Need to Know About Egress Windows

When carrying out window replacements for your home, getting familiar with the Ontario Building Code(OBC) and the National Building Code of Canada (NBCC) is an absolute must. The OBC and NBCC are in place to ensure homeowner and tenant safety and to provide you with a benchmark for completing projects successfully. egress windows are an important part of the OBC/NBCC that is unfortunately overlooked by many window companies in Ontario.

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Everything You Need to Know About Egress Windows

Here, we answer some common questions and cover everything you need to know about installing egress windows in your home.

What is an Egress Window?

First and foremost, an egress window is a life-saving addition to any home. Designed primarily as an emergency escape, it’s made in such a way that any person can quickly and easily exit the building in case of an emergency. Should your home experience a fire or flood for example, egress restrictions will ensure that the set-up of your windows won’t cause an obstruction for household members to exit safely.


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Egress Windows Types

While your preference is #1, form and function are a close second. The best replacement windows aren’t just suited to your style – they’re suited to your individual needs, too.

Luckily “egress” isn’t a type of window, it’s a category. This means that the following replacement window types (casement windows, single slider windows, double slider/end vent windows, and awning windows) can all qualify as egress, as long as the dimensions are in accordance:

Casement Windows


Awning Windows


Single Slider Windows


Double Slider Windows


Thermo-Bilt Reviews

We purchased 10 energy efficient thermal pane windows and two doors in March. The representative Mr. Barry Liburkin did a fantastic job explaining the benefits of his products. We were very happy with the installation team led by Stan and Igor. The office staff was also very friendly and we will gladly refer this company to everyone for their windows and doors needs. A job well done! Thank you.

Thomas Reinboldt

Fantastic windows and installation services! Staff were prompt, courteous, and skilled. These windows are definitely high quality but the costs were affordable. Make a point of calling this excellent company.

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We are very pleased with this company. They replaced 8 Windows in our house. Peter and his crew did a masterful job on our Bow window build. The job was done fast and efficient and we love the high quality of the product.

John Andrighetti

What Are the Egress Window Size Requirements in Canada?

The NBCC and OBC size restrictions are the same, meaning that the rules for egress are Canada-wide. According to section of the OBC, an egress window must:

“(b) provide an individual, unobstructed open portion having a minimum area of 0.35 m² with no dimension less than 380 mm, and

(c) maintain the required opening described in Clause (b) without the need for additional support.

(2) Except for basement areas, the window required in Sentence (1) shall have a maximum sill height of 1 000 mm above the floor.”

“(4) Where the sleeping area within a live/work unit is on a mezzanine with no obstructions more than 1 070 mm above the floor, the window required in Sentence (1) may be provided on the main level of the live/work unit provided the mezzanine is not more than 25% of the area of the live/work unit or 20 m2, whichever is less, and an unobstructed direct path of travel is provided from the mezzanine to this window.

(5) Where a window required in Sentence (1) opens into a window well, a clearance of not less than 550 mm shall be provided in front of the window.”

NBCC/OBC Requirements for Egress Windows

Aside from size, the NBCC dictates that bedroom windows must:

  • Provide a minimum of 5-percent LIGHT for the floor area of the room.
  • Provide VENTILATION adequate for year-round mechanical ventilation.

Meanwhile, the OBC covers important areas such as: window material, surrounding obstructions, egress window covers, window well requirements etc. To read the OBC’s complete list of rules and restrictions with regards to egress windows or doors for bedrooms click here.

To read all egress window size requirements, visit OBC’s online resource.

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How Much Do they Cost in Ontario?

There are many factors that can play in to the cost of installing an egress window in Ontario. For example, Initial installation may require grading, a drainage system and proper evacuation. During your in-home consultation, a member of the Thermo-Bilt staff will assess your needs and use them as a base for in order to calculate your egress window cost. Depending on your window type, glazing selection, and window size, the cost will change as well.

Do Basement Have to Have Egress Windows?

In a word, YES! All basement windows across Canada must be compliant with the fire code and must be egress-compliant. In fact, when it comes to basements, following egress requirements is especially important. As an area of the home that can often be confining, having a proper escape plan in place is imperative to residents’ health and safety.

Basement Egress Windows: What to Consider

The added complication with basement windows, is that they can often be partially-obstructed due to the fact that they are partially or fully below ground. In order to meet egress requirements, your window replacement company will need to determine if any additional structural changes need to be made. In some cases, for example, you may need to build out a window well to accommodate for the height difference between your basement and the ground. If your home was built before egress window requirements were put in place, your professional window installers will need to devise a plan to overcome any extra challenges or road blocks that may come up.

What is the Legal Window Size for a Basement Bedroom in Ontario

Basement window size requirements are no different from the NBCC’s and OBC’s guide for bedroom window sizes for the rest of the home. As long as you are aware of bedroom window size requirements for the rest of the home, you can assume that the same rules apply to your basement bedrooms. If you’re in need of a reminder, please refer to the chart under “What Are the Egress Window Size Requirements in Canada?”

You’ll Need a Reputable Window Installation Company in Ontario to Get the Job Done

With such intense restrictions regarding egress windows, you’ll need a trustworthy window installation company by your side to make sure that your window replacement is high-quality and up to code. Thermo-Bilt has proudly designed and installed replacement doors and replacement windows for homes all over the GTA and across Ontario for over 20 years.

We are well-versed in egress requirements, and eager to get started on your next project. To learn more, get a free quote, or request a free consultation, contact us.