Q & A : The Most Energy Efficient Windows

The average home spends 45% of their energy on heating their home. And another 9% on cooling it. If you don’t have energy efficient windows, most of that air is escaping. Make sure you get the most cost-effective energy improvements  by getting the most energy efficient windows.

Your windows alone may be responsible for up to 25% of your heating costs by letting heat escape. The same for cool air in hotter months. Enhance your comfort and health by insulating your home through window replacement or storm windows. But which provide the most energy efficient windows?

You’ve probably heard that if your windows are 30 years old you have to replace them. Old windows are leaky, rundown, and don’t have the modern technology that the new, best energy saving windows do. This isn’t necessarily true.

New vinyl windows can be cheap and no better (often worse) at insulation than old windows (especially when they are retrofitted). More expensive double-pane windows with inserted gas can help a great deal. But the gas leaks over time, and they will need to be replaced every 10 – 20 years, which is true of any replacement window. That’s why their warranties only last 10 – 20 years.

Older windows, retrofitted with storm windows, can perform as well as the most energy efficient windows on the market.

Yes. New windows will save money on energy bills. The average household saves 12% a year on their energy bill by installing new Energy Star windows. This depends on where you live, your climate, and whether you’re replacing single-pane or double-pane windows.

And do storm windows save money? Storm windows can save as much or more on energy bills without the initial high cost of replacement. Indow window inserts save 20% a year on energy bills on average. According to the Department of Energy, “Storm windows will produce similar savings at a far lower initial cost.”

Window sellers will say that virgin vinyl is the best insulator, but old-growth wood with its denser rings makes the best energy saving windows. Old-growth wood frames are sturdier and expand and contract less with fluctuations in weather.

Vinyl windows are only good insulators until their seal is broken. Once the seal has failed, so will the window’s energy efficiency. A replacement window seal often fails within 10 years of installation and the warranty only covers non-glass parts for the first 10 years.

With an interior window insert, you can recreate the seal over and over again by removing and reinserting it. This only takes minutes and restores the seal. Indow window inserts are made of acrylic panels and silicone compression tubing. Acrylic is highly durable and silicone’s ability to retain elasticity makes it perfect for sealing conditioned air in and keeping drafts out.

The debate of whether to replace your windows for the sake of energy efficiency is a relatively new one. People used to just repair and retrofit as standard practice. Most energy and home repair experts agree, storm windows vs window replacement in the fight of most energy efficient windows, storm windows win.

“Storm window installation is one of the most cost-effective solutions for upgrading energy inefficient existing windows. They’re easy to install and cost a fraction of replacement windows.” –Department of Energy

As for return on investment, Scott Sidler who has worked on homes professionally for 10 years wrote, “The payback period for the new windows is 40.5 years. The payback period for the storm window is 4.5 years.”

Older windows also have fewer moving parts that can break and are easier to maintain. If taken care of or restored, a 100 year old window can last another hundred years. Storm windows can prolong the life of the window and bring its energy efficiency up to that of a double-pane.

The most energy efficient windows for one home aren’t going to be the most energy efficient windows for another. Age of the home, climate, and what other insulation projects you’ve already completed all factor in.

Scott Sidler has a great storm window guide. The Department of Energy has many tips on energy savings through windows and other home improvements. You can also contact us if you’re interested in getting a quote for energy saving window inserts.