Install a Basement Window: DIY or Hire a Pro?

Handy homeowners may be looking at their old basement window and thinking, “I can probably install a new one myself.” But it depends on the situation. If you need to install a basement window where none exists or replace a smaller window with a larger one, then you almost certainly need help from a professional. If you are simply replacing your basement window with a newer one that is the same size, then yes, a skilled DIYer may be able to handle it. Here’s what to know.

Do You Need to Install a Basement Window for Egress?

If you are using your basement as any kind of habitable living space — like as an office, a bedroom, or a living room — then you, you need a window that meets egress requirements. Simply put, you need a window of a certain size so that you can easily escape through it if you need to.

You cannot DIY an egress window. Here’s why:

1. It’s a matter of safety. A window that is not installed properly or that is not quite large enough may not function as intended. You need to be able to get out of it quickly and easily in an emergency, and first responders may also need to use the window to get to you. There are lots of ways to save money when you are finishing out a basement, but your egress windows are not one of them.
2. You may run into structural support beams during installation. While the opening for a window can typically be widened without issue, increasing the height — which you will likely need to do to meet egress — can cause real damage if you don’t know what’s up there or when/where to cut.
3. Your home may be made of masonry. Unless cutting through masonry exteriors is a key part of your full-time profession, you should not attempt it.
4. You may need to excavate a window well. If you do not currently have an egress window in your basement, then part of meeting requirements is having a window well. You will need an area excavated around the outside of where your window is going to have one installed.

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How to Install an Egress Window

If you’re curious what the process to install an egress window looks like or are wondering how long your contractor may need to complete the project, here are the basic steps for how to install an egress window.

1. Obtain permits. Building codes and regulations vary, and obtaining the necessary permits is crucial for a compliant and safe installation.
2. Choose the location: Your egress window installer will help you choose where the window goes. Consider the room’s layout, interior design, and exterior obstacles like trees or utility lines. The location should allow for an unobstructed path to exit in case of emergencies.
3. Excavation and foundation cutting. Work will begin by excavating the exterior area to create a window well. Your contractor will then cut an opening in the foundation wall to the desired window size .
4. Prepare the window well. You will choose a pre-made window well or design your own. Then, the window well liner will be installed against the foundation wall. These liners help to prevent water accumulation and soil erosion.
5. Install the window. The egress window will then be placed into the prepared opening. Your contractor will attach it to the basement window framing using screws or nails.
6. Weatherproofing and insulation. A waterproof sealant should then be put around the window frame to prevent water infiltration. Weather-stripping will ensure a tight seal when the window is closed, and you can also add insulation around the window frame for extra energy efficiency.
7. Backfill and grading. Once everything is installed, your contractor will backfill the window well with gravel, ensuring proper drainage. They will ten grade the surrounding area to direct water away from the window well.
8. Interior finishing. Finally, the interior finishing, such as adding trim or drywall, will be done to create a finished look.
9. Final inspection. Once the project is complete, your contractor will help you schedule a final inspection with the local building department to ensure the egress window installation meets all code requirements and safety standards.

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How to Replace a Basement Window

If you do not need an egress window, or if you already have a completed egress window and are simply replacing it, then a homeowner with the necessary experience may be able to tackle this project. Here is how to install a basement window that does not need new egress.

1. Measure and purchase a new window. Measure the existing window opening carefully to ensure you purchase the correct size replacement window. Consider choosing a window designed specifically for basement use, as they often have features to improve energy efficiency and protect against moisture.
2. Remove the old window. Use a pry bar and hammer to carefully remove the old window frame and any trim around it. Take your time to avoid damaging the surrounding wall or interior finishes.
3. Inspect the window opening. Check the condition of the window opening and the surrounding wall. Repair any damaged or rotted areas, and make sure the opening is clean and free of debris.
4. Install the new window. Follow the window manufacturer’s instructions for installing the new window. Some windows may come with an installation kit that includes the necessary hardware. Insert the new window into the opening and use shims to ensure it is level and plumb.
5. Secure the window. Use screws or nails to secure the new window to the basement window framing. Follow the manufacturer’s recommendations for the type and size of fasteners to use.
6. Weatherproofing and insulation. Apply exterior-grade sealant around the window frame to prevent water infiltration. Install weather-stripping to ensure a tight seal when the window is closed.
7. Finish the interior. If necessary, add interior trim or casing around the window to complete the finished look.
8. Seal and caulk. Seal any gaps between the window frame and the surrounding wall with silicone caulk. This helps prevent air leaks and further weatherproofs the window.
9. Test the window. Open and close the new window to ensure it operates smoothly and locks securely.

Egress Window Installers

If you are installing a new basement window where none exists or ensuring your basement window meets egress requirements, then you need to get quotes from egress window installers.

We recommend you ask any basement egress window installers for pictures/examples of their previous work, ensure they have installed these kinds of windows before, and ask them to break down their quote into labor and materials. That will allow you to evaluate several quotes fairly.

If you want to be matched to vetted egress window installers in your area who have availability for your project, Modernize can help. We will match you with up to four pros so you get the best price as well as to find someone you truly like. You can also browse our directory of egress window installers and pick a pro yourself.

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