How to Install Energy-Efficient Windows in an Old House

Upgrading an old house with energy-efficient windows is one of the best ways to improve insulation, reduce energy costs, and enhance comfort. Older homes often have outdated single-pane windows that allow heat to escape in winter and enter in summer, making energy bills soar. Replacing them with modern energy-efficient options can help retain indoor temperatures and lower utility expenses. Here’s a step-by-step guide on how to install energy-efficient windows in an old house while preserving its charm.

Why Upgrade to Energy-Efficient Windows?

Before diving into the installation process, it’s important to understand why energy-efficient windows are a great investment:

Lower Energy Bills: These windows prevent heat loss, reducing the need for heating and cooling.
Improved Comfort: They minimize drafts, cold spots, and excessive heat.
Better Noise Reduction: Advanced window designs reduce outdoor noise.
Enhanced Home Value: New windows improve curb appeal and property resale value.
Eco-Friendly: Reduced energy consumption lowers your carbon footprint.

Step 1: Assess Your Current Windows

Before purchasing new windows, evaluate the existing ones. Check for drafts, rot, condensation, and cracks. If the window frames are still in good condition, you may only need to replace the glass or add storm windows rather than replacing the entire frame.

Step 2: Choose the Right Energy-Efficient Windows

When selecting energy-efficient windows for an old house, consider the following features:

Double or Triple Pane Glass: Multiple panes with gas fillings (like argon or krypton) provide excellent insulation.
Low-E Coatings: These coatings reflect infrared light, keeping heat inside during winter and outside during summer.
Frame Material: Choose from vinyl, fiberglass, wood, or composite materials based on insulation properties and aesthetics.
ENERGY STAR® Certification: Look for windows that meet ENERGY STAR® requirements for maximum efficiency.

Step 3: Take Accurate Measurements

To ensure a perfect fit, carefully measure the window openings:

Width: Measure at the top, middle, and bottom of the window frame.
Height: Measure on the left, right, and center of the frame.
Depth: Check the thickness of the existing window frame.

Use the smallest measurements to avoid ordering windows that are too large.

Step 4: Remove the Old Windows

Prepare the Area: Cover the floor and furniture with drop cloths.
Remove the Sash: Take out the window sash and any existing storm windows.
Detach Trim & Stops: Carefully remove interior and exterior trim using a pry bar to avoid damaging the walls.
Take Out the Old Frame: Unscrew or pry out the old window frame while ensuring the opening remains intact.

Tip: If the window opening has rot or damage, repair it before proceeding.

Step 5: Prepare the Window Opening

Check for Structural Issues: Ensure the frame is level and square.
Seal Gaps: Use spray foam insulation or caulk to seal gaps around the window opening.
Install Flashing Tape: Apply flashing tape around the perimeter of the opening to prevent water infiltration.

Step 6: Install the New Energy-Efficient Window

Place the Window: Insert the new window into the opening and ensure it fits snugly.
Check for Level and Square: Use a level and shims to make adjustments.
Secure the Window: Screw the window into place according to the manufacturer’s instructions.
Seal the Gaps: Use caulk or insulation foam to fill any remaining spaces around the window frame.
Replace the Trim: Reattach the interior and exterior trim to maintain the home’s original appearance.

Step 7: Apply Final Touches

Test the Window: Open and close the window to ensure smooth operation.
Add Weatherstripping: This helps improve insulation and prevent drafts.
Paint or Stain the Trim: Match the new window trim with the existing home aesthetics.

Step 8: Maintain Your New Windows

To keep energy-efficient windows performing well:

Clean Regularly: Use mild soap and water to clean window frames and glass.
Inspect Seals Annually: Look for gaps or air leaks and reseal if necessary.
Check Hardware: Lubricate hinges and locks for smooth operation.

Final Thoughts

Installing energy-efficient windows in an old house enhances comfort, saves energy, and increases home value. By following the proper steps—from choosing the right windows to careful installation—you can preserve the charm of your home while modernizing its efficiency. Whether you tackle the project yourself or hire professionals, the benefits will be long-lasting.