How to Install an Exit Window

Before You Start

Adding an egress window is a big job, and it’s important to plan your project to meet the building requirements in your location. Here are the steps I took before starting to excavate:

Apply for a permit

This process could take a few weeks. My city required detailed plans of the well, the dimensions of the window and rough opening, the size of the header and a drawing of the property, including the house.

Engineered drawing

The retaining walls that made up our well were tall enough to require an engineer’s approval. I sent my plans to a local engineer who gave me a new drawing with a stamp of approval to include with my permit ­application. If you buy a manufactured well, this step is likely unnecessary, but your city’s building department makes the final call.

Call the digging hotline

When you’re digging, even just a few inches, call to have underground utilities located and marked.

Digging is dangerous if you don’t know where the utilities are. If you skip this step and hit a gas, water, or power line underground, you’ll risk the lives of yourself and others, and you’ll be on the hook for the costly repairs. So be sure to call 811 before your project. The process varies by state, so call a few days ahead of your project.

Requirements for Egress Windows

Here are the minimum requirements identified by the building code: 

• The opening needs to be 5.7 square feet.
• The minimum width is 20 inches.
• The minimum height is 24 inches. 
• The well needs to provide a clear space of 3-ft. x 3-ft. when the window is open.
• From the inside, the sill height cannot exceed 44 inches