Window Replacement Step-By-Step Guide

Window Replacement Step-By-Step Guide

Have you decided to replace those old, drafty windows in your home? That’s great because new energy-efficient windows can significantly affect your home’s comfort and energy usage.

Some cities often experience extreme weather conditions, like heavy rainfall. For instance, Pittsburgh receives an average of 38 inches of rain annually. Moisture from rain, along with the potential for snow during the winter months, seeps into cracks or deteriorates the window frames. Due to such unforeseen weather conditions, replacing your windows from time to time is crucial to ensure better insulation and protection against the elements.

We’ll walk you through all the crucial steps required for a window replacement task.

When to Call a Professional

Eventually, even the handiest DIYers will encounter issues beyond their abilities or available tools. For window replacement, it’s best to call in a professional if:

1.     You’re dealing with rotted or damaged frames

Removing and replacing rotted wood or damaged metal window frames requires skill and the proper equipment to do so safely and effectively. Consulting with renowned window replacement experts in your region is advised.

If you live in Pittsburgh, look up Pittsburgh Window Replacement near me and hire a professional with the experience to assess and repair the damage. They’ll remove the old frames properly and install new frames that are securely fitted.

2.     Permits or inspections are needed

Most areas require permits for window replacement to ensure it meets building codes. Professionals will handle obtaining the proper permits, scheduling inspections, and making necessary adjustments to pass inspections. They stay up-to-date with the latest regulations to ensure your new windows are safely and legally installed.

When Is It Time to Replace Your Windows?

It’s time for new windows when your current ones show signs of age or damage. If you notice any of these issues, replacement is probably a good idea:

1.     Draftiness

Is cold air seeping in through the edges of your windows? That means they’re not insulating well anymore. New windows can lower your heating bills and make your home more comfortable.

2.     Difficulty Opening or Closing

If your windows stick, jam, or won’t lock properly, it’s a hassle and a security risk. Modern windows can slide or open and close smoothly.

3.     Fading or Cracks

Visibly damaged or deteriorating windows reduce your home’s curb appeal and resale value. Updating them with attractive, durable replacements gives your house an instant facelift.

Measure the dimensions

To remove your old window, first, you’ll need to measure the measurements to know what size replacement window to purchase.

First, score around the edge of the window frame with a utility knife to break the seal of any paint or caulk. Next, remove any trim, sills, or molding around the window. Apply pressure to loosen the window in its frame, then have an assistant help lift out and dispose of the window.

Before starting the process, Wear protective gear like work gloves, eye protection, and old clothes. Be extremely cautious when handling and removing glass. Clean the opening thoroughly by scraping off any remaining caulk or debris. Lastly, measure the opening again to double-check the size of your new window.

Choosing the Right Windows for Your Home

When choosing windows for your home, you have a lot of options. Do you want double-hung, casement, sliding, or awning windows? Wood, vinyl, or fiberglass frames? Clear, tinted, or low-E glass? The choices can be overwhelming.

Focus on these key factors:


Choose a window style that complements your home’s architecture. Double-hung and casement windows suit traditional homes, while sliders are more contemporary.

Frame material

Wood frames are attractive but require maintenance. Vinyl and fiberglass are low-maintenance. Composite or aluminum frames offer a good price.


Choose double-paned windows with a low-emissivity (low-E) coating for energy efficiency and cost savings. Low-E glass lets in light while blocking heat transfer. Tinted or reflective glass reduces glare and heat but also light transmission.


Consider your local weather conditions. Double-paned or triple-paned windows with thermal breaks are best for insulation in cold climates. Solar control low-E glass is suitable for hot climates.

Insulate Window Frame Voids and Dry Fit a Window

Now that the old windows are out and the rough opening is prepped, it’s time for the new windows. But before installing them, you need to insulate the window frame voids and do a dry fit to ensure proper sizing.

Insulate the voids around the rough opening in the wall to improve the window’s energy efficiency. Fill gaps around the frame with low-expansion foam sealant, weatherstripping tape, or fiberglass insulation. Make sure to seal up any air leaks for maximum insulation.

Do a dry fit by placing the new window into the opening before permanently installing it. This step allows you to ensure the window is level and fits properly without any gaps. If needed, you can make minor adjustments to the rough opening size. It’s much easier to modify the opening now versus after the window has been installed.

Once the dry fit is complete and the window frame voids have been insulated, you can install and seal the new window.

Set the window and fasten it

To attach the window, you’ll want to start with the corners. Place a screw through the top corner of one side, screwing into the frame. Do the same for the opposite top corner. Check that the window is still level, then secure the bottom corners.

With the corners in place, you can add screws along the sides of the window every 6 to 8 inches. As you go, ensure the gap between the window frame and the wall opening remains even around. For the most energy efficiency, any space should be minimal.

Add backer rod and caulk

Before applying caulk around the window, you’ll want to insert a backer rod. This rope-like material helps fill gaps to create the proper shape for the caulk bead.

  • Measure the gap between the window frame and the siding or wall surround. Purchase a backer rod that is slightly larger than your gap size.
  • Compress and insert the backer rod into the gap around the window frame. Use a putty knife, caulk tool, or your fingers to push it into place gently.
  • Leave about 1/4 inch of the backer rod protruding from the gap. Make sure the backer rod is evenly placed around the window.
  • Use a utility knife to trim any excess backer rod flush with the siding or wall surface.
  • Load the caulk into a caulk gun and cut the tip at a 45-degree angle to dispense the right amount. Then, apply a thick bead of caulk around the outer edge of the window where it meets the siding. Use a wet cloth to smooth out the caulk, sealing any gaps and creating a professional finish.


While it may seem intimidating, your new windows will be installed quickly if you take it slow and follow each step carefully. The key is to measure accurately, choose high-quality and energy-efficient windows that suit your needs, and the installation area properly. However, getting the experts to do this task is better and less costly.  

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