Double-pane windows have lots of great benefits and will increase the value of your home. But they also have drawbacks that window companies fail to mention when promoting them and touting their energy savings. As a REALTOR, I get to see how they function (or sometimes don’t) in homes.
Double-Pane Window Benefits
Energy Efficiency
Double-pane windows are certainly more energy efficient than single pane windows, but the energy cost savings isn’t very high if you live in an area with a mild climate like San Diego County.
Improved Sound Quality
Windows with double-panes will keep your home quieter than those with single panes. If the windows are filled with argon or krypton gas, they will help block even more sound. But they don’t block all the noise. If you need to block sound, look into soundproof windows.
More Comfort
Many of today’s double-pane windows have low-emissivity (low-e) coatings and more efficient window frames. This helps limit cold air pockets and air leakage near windows.
Better Security
Double-pane windows are stronger than their single pane counterparts and more difficult to shatter. They’re also better sealed, making it harder to force them open.
UV Protection
Sunlight can damage and fade furniture, flooring and art. Double-pane windows with low-e coatings block a lot more of those damaging UV rays than older, single-pane windows.
Higher Home Value and Aesthetics
Remodeling’s 2021 Cost vs. Value Report gives a high return for replacing older windows with new, low-e windows. Many home buyers today expect homes to have double-pane windows and will pay more for homes that have them. Plus, your home will just look better.
Double-Pane Window Downsides
High Costs
Yes, double-pane windows are more energy efficient than single-pane windows and will lower your energy costs. But it’s expensive to install them in your home, and it will take many years to recoup the money spent with those lower energy bills.
Shanon Peterson Waseilweski did a cost/benefit analysis for a home in Nashville, Tennessee. She estimated it would take 70 years for the energy savings to pay for the cost of the windows.
Energy Star and D & R International calculate that here in San Diego replacing single-pane, aluminum framed, clear windows with double-pane Energy Star windows would save you $107 per year. Modernize gives the average cost for a vinyl, double pane window as $618. And that doesn’t include installation. So, if you live in an area with weather like ours, don’t expect the cost of energy savings to pay for those new windows for decades.
Seals Fail and Are Expensive to Repair
Lifespan estimates for gas-filled, double-pane windows seem to range from 10 to 30 years, and there are many factors which can affect how long their seals last. The International Association of Certified Home Inspectors also says that gas-filled windows will leak as much as 1% per year.
What I’ve seen in the resale homes I’ve sold and shown is that the seals in many of these windows fail and this can happen in as little as 10 years. When the seals between the two window panes fail, it’s common to see moisture, hazing or fogging between the two pieces of glass. This fogging makes the windows look dirty and can make it difficult to see through the window.
Repair or replacement of windows with broken seals is expensive. So, if you are going to replace your windows with double-pane glass or are buying a home that already has these windows, check the manufacturer’s warranty. What is the coverage for the window glass and components? Is installation covered? Does the warranty transfer beyond the original purchaser?
I recently sold a home that was built just 16 years ago. The seals had failed in most of this home’s windows. The cost to replace the glass for those windows was between $15,000 and $20,000.
While I don’t usually see that many broken window seals in homes of that age, I have found some broken seals in double-pane windows in homes that are only 10 to 15 years old. So, although they have many benefits, double-pane windows also have some expensive drawbacks.