Applying caulk around windows lowers home energy costs by stopping air leaks, which otherwise allow heat to escape in the winter. ... Sealing air leaks not only saves energy — it leads to a healthier, more durable home.

Should I caulk the inside of my windows?

Yes, it's best to apply caulk to both the interior and exterior when installing new windows. This will seal any unwanted air leaks. Using a caulk gun will ensure you fill any gaps and get a clean line. Watch this helpful video to learn the right way to use a caulking gun.

How much energy does caulking improve?

You can save 5-10% on your energy bill or 7.5% on average by fixing air leaks with weather-stripping and caulking.