Egress Window Basement: Requirements, Costs, and Installation Guide

A basement egress window is an emergency-exit window that meets specific size, height, and operability requirements under Canadian building codes. In most cases, it must provide a minimum unobstructed opening of 0.35 sq m (3.77 sq ft), with no dimension less than 380 mm (15 in), and be openable from the inside without keys or tools. Below-grade basement windows require a properly sized window well.

requirements can vary by location, so always confirm the applicable building code before installing or replacing a basement egress window.

In this guide, you'll learn everything you need to know about installing an egress window in the basement.

Quick Facts: Basement Egress Window Requirements

• Suitable basement egress window options include casement, sliding, and hung windows, provided they meet opening requirements. However, only the openable portion of sliding and hung windows counts toward the egress opening.
• Given the structural complexity and code compliance involved, hiring a professional is highly recommended to ensure safe, legal, and efficient installation, especially when cutting new openings or installing window wells.

What Is An Egress Window?

Egress windows serve as emergency exits. They must meet specific size and functional criteria, which are established by local building codes. Egress window requirements generally apply to bedrooms and other rooms where an emergency escape opening is required by applicable building codes. Basement bedrooms are a common example.

While bedrooms or living rooms may have French doors or other doors that lead directly outside, basements only have windows. Therefore, if you have a basement bedroom, it needs a window that meets egress requirements.

While egress window requirements are similar for all spaces in terms of size, there are additional requirements for basement egress windows.

Before we discuss more about egress requirements for basement windows and window wells, keep in mind that these may vary based on location. Therefore, it is best to check local building codes before installing egress windows. For example, if you live in Ontario, make sure to consult the Ontario Building Code or check our guide focusing on the legal basement window size requirements for Ontario.

Basement Egress Window Requirements

As per the National Building Code of Canada, an egress window in the basement must:

• Provide an unobstructed clear opening of a minimum area of 0.35 sq m (3.77 sq ft).
• Not be higher than 1.5 m (4.9 ft) above the floor level (if it is higher than that, there should be something under it that one could climb onto to easily reach the window).
• Have a width and a height of at least 380 mm (15 in).
• Be easily openable from the inside without any keys, tools, or special knowledge.
• Maintain the required opening without the need for additional support.
• Have a window well if it is below ground level.

What Are the Basement Window Well Requirements?

All basement windows that are below ground level must be surrounded by a window well. This is an excavated space around the window that allows you to escape the basement in case of emergencies. According to building codes, a window well must:

• Have at least 760 mm (30 in) of clearance.
• Have enough space for the window sash to open without obstructing the clearance.
• Have a protective enclosure that can be easily opened from the inside without special tools or knowledge.

Real-Life Examples for Basement Egress Windows

Here are some windows that can serve as egress windows in the basement:

• Egress casement windows or tilt-and-turn windows measuring 600 mm x 1,000 mm with an area of approximately 0.6 sq m
• Sliding windows measuring 1,200 mm x 700 mm with an unobstructed clear opening of 0.42 sq m (don't forget that only half of the opening can be accessed at one time)
• Single-hung windows measuring 900 mm x 900 mm, but only if the opening area represents half of the window's height

These windows do not qualify as egress windows in the basement:

• Awning windows or hopper windows that open only up to a 45-degree angle
• Sliding windows measuring 900 mm x 600 mm because only half opens, and it accounts for only 0.27 sq m of clearance
• Fixed windows
• Casement windows measuring 380 mm x 380 mm with an area of 0.144 sq m (even if they meet the size requirements in terms of mm, they do not meet the area requirements of 0.35 sq m).

Keep in mind that you should not calculate the opening area based solely on the window width and height; you should also consider the frame thickness, for example. Vinyl window frames, for instance, are bulkier, which means that a vinyl window of the same size as a Magic window will have a smaller opening area.

Types of Egress Windows for Basements

If you need to install egress windows in the basement, you can choose among several types of basement windows, including casement windows, sliding windows, or single-/double-hung windows. Below, you'll find more details about each.

Casement Windows

Casement windows are one of the best options for egress windows. They are hinged on one side and open outwards like a door. This means that they provide a large, unobstructed opening for a safe and easy escape during emergencies. Plus, they can significantly improve ventilation.

One major downside, however, is that standard casement windows come with a crank mechanism, which is not the best choice if the window is an egress window. Traditional crank-operated casement window require the hardware to be operated before the sash can be opened. For an egress window, homeowners may prefer an operating mechanism that allows the window to be opened more quickly and easily.

For homeowners considering casement egress windows, crankless operating systems are another option to consider. The operating mechanism should allow the window to be opened easily from inside during an emergency.

If you want to install casement egress windows, keep in mind that the window well should be large enough for the window sash to not obstruct the exit.

Slider Windows

Slider windows can also be installed as egress windows. They have two sashes and operate by sliding horizontally, providing plenty of natural ventilation and light. Because of their opening mechanism, sliding windows are often preferred over casement windows because they do not open into the window well. Moreover, you can easily open a slider window, which is extremely important in case of emergency.

However, one key consideration with slider windows is that only half of the window opens. This means that the egress requirements apply only to the half that can stay open.

Hung Windows

Hung windows operate similarly to sliding windows, except that they slide up and down. They are not usually installed in the basement because they are taller than they are wide. However, if there is enough space to install a hung window as an egress window, you can definitely do so.

Like in the case of sliding windows, only half of the window opens at a time. Because of this, only that openable portion is taken into consideration in terms of egress requirements. Therefore, an egress hung window will be twice as large as a casement egress window.

Things to Consider Before Choosing Basement Egress Windows

Here are some things to consider before choosing basement egress windows:

• The window frame. If the window frame is bulky, you'll have to install larger windows that meet egress requirements. If you're looking for slimmer frames, you can install Magic windows, which are among the thinnest on the market.
• The bug screen. You have to be able to remove the bug screen easily and quickly. For example, Magic bug screens are fully retractable. This means that, in the case of fire or other emergency, all you have to do is push the screen back into its cartridge (which is installed on one side of the frame), and it will slide seamlessly along the frame. This only takes a second. Or, even better, you can keep the bug screen hidden within the cartridge when the window is closed. This way, if you need to escape the basement, you won't have to worry about the bug screen.
• Security features. While it's extremely important to have high-quality window locks to prevent break-ins, you and your family, including your kids, should be able to open them easily.

Window Wells for Below-Ground Egress Windows

As mentioned above, window wells are necessary for escape windows that are below ground level. They maximize the amount of light coming through the window, provide adequate ventilation, and ensure a safe escape route at ground level.

A window well usually has a U shape. It is supported by a plastic or curved metal wall. Some window wells have stairs or ladders.

Installing a window well can be quite difficult, so it's best to contact a professional company that can take care of everything.

They will first assess the window location, ground slope, soil type, and landscape. Then, they will start the excavation process and install the drainage system, which is extremely important to prevent water buildup in the window well. If water accumulates in the window well, it won't serve as a safe and easy exit anymore.

In the end, the team will secure the window well to the house, making sure it is aligned properly.

Professional Installation vs. DIY

When it comes to basement windows that serve as egress windows, our recommendation is to hire a professional team to do the hard work. While DIY installations can save on labor costs, they may lead to safety risks and potential errors without professional oversight.

Hiring a professional is advisable for egress window installation because:

• The installation may involve complex structural modifications like cutting through the foundation, excavating for a window well, or installing a drainage system.
• Local regulations might be unclear.
• Professional installers can complete the installation quicker, reducing disruption in the homeowner’s daily life.

Compliance with building codes and safety standards is another reason why most homeowners opt for professional installation.

Ultimately, when expertise and precision are necessary, hiring a professional is the best choice.

Basement Egress Window Replacement Costs

In Canada, a basement egress window costs, on average, between $500 and $2,500 or more, depending on the window, installation requirements, and location. Additionally, installing a window well costs approximately $1,000-$3,800, depending on excavation needs, drainage system, materials, and site condition.

The price to install a basement egress window depends on:

• Window type
• Window size
• Frame materials
• Glazing options (e.g. double-glazed, low-E glass)
• Window well size and requirements

If you need an egress window and want a free quote for a replacement, you can book a free consultation with Magic! One of our experts will take into consideration all the necessary details and provide you with all the necessary information!

Frequently Asked Questions

Does every room in a basement need an egress window?

Not every room in a basement needs an egress window. Only habitable rooms in a basement, such as bedrooms or living areas, require an egress window.

What is the minimum size for a basement egress window in Canada?

Basement windows in Canada must have a minimum unobstructed opening of 0.35 sq m (3.77 sq ft), with no dimension less than 380 mm (15 in).

What makes a basement window egress?

A basement window qualifies as an egress window when its unobstructed clear opening, sill height and operation meet the applicable building-code requirements. It must also be openable from inside without keys, tools or special knowledge.

What is the code for basement windows in Ontario?

The Ontario Building Code requires basement egress windows in bedrooms to have a minimum clear opening of 0.35 sq m (3.77 sq ft), have a maximum sill height of 1.5 m (4.9 ft), and be openable without keys, tools, or special knowledge.

How many egress windows are required in a basement?

Each bedroom in a basement requires its own egress window for safety in emergencies.

Why are window wells necessary for below-ground egress windows?

Window wells are essential for below-ground egress windows as they provide natural light and a safe escape route, ensuring compliance with building regulations. Adequate depth and width are crucial for safety and accessibility.

What are the benefits of hiring a professional for egress window installation?

Hiring a professional for egress window installation guarantees adherence to building codes and efficient handling of structural modifications, as well as minimizes disruption to your daily routine.

What is the clear opening of an egress window?

The clear opening of an egress window is the actual unobstructed space available for escape when the window is fully open. It is not necessarily the same as the window's overall frame-to-frame dimensions. Window frames, hardware, and other components can reduce the usable opening, so the clear opening should be measured when the window is in its required open position.