Basement egress windows: sizes, wells and permits in Alberta

Every basement bedroom needs a way out in an emergency. That's why the building code sets a minimum size for bedroom windows, and why many basement developments start with enlarging one.

The minimum opening

• At least 0.35 m² (3.77 sq ft) of unobstructed opening.
• No side of the opening smaller than 380 mm (15 in).
• It must open from the inside without keys or tools.
• An exterior door that opens from the inside can take the place of the window.

Rooms that aren't bedrooms, like a rec room, bathroom or laundry room, don't need an egress window.

Window styles

Horizontal and vertical sliders are fine, as long as the part that opens meets the minimum size on its own. Casement and awning windows must open a full 90°, and an awning window must stay open without being held.

Window wells

When the window opens into a window well, there must be at least 760 mm (30 in) of clear space in front of it so a person can climb out. EPCOR also recommends that the top of the well sit 3–4 inches above the ground, that the well extend at least 12 inches below the window, and that the bottom be filled with washed rock. A cover keeps out snow and rain.

Permits

In Edmonton, adding a window or changing its size needs a permit, while replacing a window with the same size doesn't. Enlarging a basement window means cutting the foundation, which is structural work, so expect a permit wherever you live. Your builder confirms what your municipality requires. The new window then has to meet the egress rules above.

Before any digging

Buried gas, power and communication lines must be located first. Utility Safety Partners marks them for free, but requests need at least three full working days. Locates don't show depth, so digging near the marks is done by hand.