Energy Efficient Windows

Guide to Energy Efficient Windows in Western Washington

These are some of the questions we’re going to be answering in this guide to choosing the best energy-efficient windows for your house. Let’s address the most important question first: what are Energy-Efficient Windows and how do they save me money?

Depending on the time of year, you’ll either be spending energy (and money) to keep your house warmer or cooler than outside. Maintaining comfortable temperatures indoors is difficult due to 3 issues: Air Leakage, Direct Sun Rays (Radiation), and Convection Currents. Standard windows, old windows, and improperly installed windows are all prone to these energy issues. Replacing them with properly installed Energy Efficient Windows will solve these problems and save you money.

Energy-efficient windows use a combination of clever solutions to maintain your home’s temperature  for longer, resulting in lower energy costs:

  • Window glazes
  • Tightly-sealed edges 
  • Insulated frames
  • Filling the gap between the window panes with inert gasses

Types Of Energy Efficient Windows

Energy-efficient windows have the same operating styles as traditional windows like awning windows, single and double-hung windows, etc. While the way the window opens will have an effect on air leakage (awning windows generally have very low air leakage), their overall contribution to energy-savings is limited. The real savings come from advanced energy-efficient technologies.

energy efficient window types infographic

3 Technologies Used in Energy Efficient Windows

Energy-efficient windows can be categorized on the basis of the technologies they use as such:

Gas-Filled: Some windows use an inert gas to fill the space between the panes in double and triple-glazed windows. Inert gasses are better insulators than air, so they stop radiant heat from passing through the window. The most common gasses used in these windows are Krypton and Argon.

Energy-efficient windows with argon will be cheaper, while those with krypton will be more effective at blocking radiant heat.

Double vs Triple Glazing: A double-glazed window will have two panes instead of just one. This serves 2 benefits. First,  the additional glass pane significantly reduces the UV rays that can pass through the window. This keeps your home cooler in the summer. Second, the double-glazed window will stop the warm air in your home from dissipating out. This saves you money on heating costs during cooler months (October-April).

Triple-glazed windows take it a step further by adding an additional pane. This can stop up to 95 percent of all the harmful UV rays. 

Low Emissivity Windows: Low emissivity, or low-E windows, will have an additional layer of metal or plastic coating between the panes of glass in double and tripled-glazed windows. Low-E windows will be up to 40 percent more efficient than standard double-glazed windows. We highly recommend Low-E Windows to save energy. 

Cost Of Energy Efficient Windows 

The most important question to most purchases: “What’s it going to cost me?”

Energy-efficient windows in Seattle, including labor, can cost between $400 and $600. This includes replacing your current vinyl window frames with double-glazed energy-efficient windows. The cost of a triple-glazed window will be between $500 to $800. Of course, the price will vary with different frames, the gases used between the panes (if any), low-E coating, etc. It’s also more cost-effective to replace all the windows in your home versus just a few because the labor is very similar. 

Keep in mind that the upfront purchase and installation costs of energy-efficient windows paint only half the story. In order to get the true cost of installing energy-efficient windows, you’ll need to consider all the cost benefits you’re getting.

Annual energy savings chart infographic replacing windows in home

How Much Money Can I Save With Energy Efficient Windows?

Let’s look at some of the factors that will affect the cost benefits you can expect by replacing your standard windows with energy-efficient windows.

1) Energy Saved = Money Saved

The average utility bill in Seattle, WA for a 4 bedroom house is $365 is 2019. And since on average you would be saving 12 percent every year by using energy-efficient windows, the actual money saved would be over $500!

Of course, there are other factors that will increase the overall money saved over the years. One factor would be the overall size of the house and the number of windows installed – people with bigger houses would be in for even greater savings.

Another important factor is the type and age of your current windows. Homeowners with standard windows that are old and are not as weather-proof as they once used to be would benefit greatly from replacing these with energy-efficient windows. EnergyStar estimates replacing old single-pane windows with double-glazed windows would decrease utility bills by over 31 percent!

2) PSE Window Rebate for Energy Efficient Windows

Puget Sound Energy offers a window rebate of $50 per window, up to $750, when you replace your old windows with energy-efficient windows. They must contain a U-factor of 0.30 or lower, which most do.

3) Reducing Noise

A double-glazed window can significantly reduce the level of outside noise and also improve the rigidity of the window. The peace and quiet provided by these windows can be invaluable if you live in a loud neighborhood or near a freeway.

4) Increasing Home Value

If the monthly energy savings aren’t enough to convince you, then you’d be delighted to know energy-efficient windows increase the value of your home significantly. 

Homeowners actually recoup up to 85 percent of your initial investment.  That means a $10,000 investment in energy-efficient windows can bump up the asking price on your home by $8,500, making these windows incredible value for money.

Homebuyers are willing to pay for a (relatively) small increase in the upfront value in order to save money in the future. The added benefits of noise reduction and potentially making back this money when selling the house in the future are a great benefit.

For typical homes, choose ENERGY STAR and save on average*:

1,006–6,205 pounds of CO2

which is equivalent to 51 to 317 gallons of gasoline

a year when replacing single-pane windows
246–2,001 pounds of CO2

which is equivalent to 13 to 102
gallons of gasoline

a year when replacing double-pane, clear glass windows

* Ranges are based on the average savings among homes in modeled cities. Actual savings will vary based on local climate conditions, utility rates, and individual home characteristics.


How To Choose Energy Efficient Windows

If you’re ready to purchase new windows, it’s important to know what options are available. In Western Washington, there are two major manufacturers that offer a wide range of energy-efficient windows: Milgard and Provia.

1) Milgard Energy Efficient Windows

Founded in 1953, Milgard is one of the top names when it comes to innovations in the industry. All of Milgard’s windows adhere to ENERGY STAR® v6 requirements that meet or exceed U-Factor and Solar Heat Gain Coefficient (SHGC) criteria. 

And remember the low emissivity coating we talked about earlier? That comes standard in all of Milgard’s double-glazed windows, known as the Low-E2 Glass. According to Milgard, this coating can reduce UV rays by up to 84 percent.

Installation Process For Energy Efficient Windows 

When you’re spending thousands of dollars on windows that will last for decades, it’s critical that it’s done right. Lake Washington Windows & Doors has a meticulous window replacement process that features our patented Leak Armor installation method. This ensures that your frames are air-tight and will not leak during long periods of rain. Seattle summers can warp window frames that aren’t installed properly, resulting in energy loss that negates the purpose of buying these windows in the first place.

It’s critical that you choose a reputable company you can trust for this job. If you ever have an issue, you want to know that your installation company will still be in business. We’ve been serving Western Washington since 2008 and we’ve only been expanding. You can count on us to install your new windows properly so you can enjoy the energy savings for years to come.  Get a consultation and quote here to begin the process.

A good window replacement company will take into consideration the direction each window will be facing. You want windows with high SHGC (solar heat gain coefficient) for the south side and low SHGC for east and west-facing windows.

Frames For Energy Efficient Windows 

The frames of your energy-efficient windows will play a big role in determining their effectiveness. As a general rule of thumb, fiberglass and vinyl offer the best insulation, followed by wood, and finally aluminum and other metal frames. However, aluminum and other metals have poor insulation so it’d be best to stick with fiberglass, vinyl, or composite wood (more durable than normal wood).

What are the most energy efficient windows?

Windows with an R-value of 5 are some of the most energy-efficient windows.

What are the most energy efficient window frames?

Fiberglass window frames are the most energy efficient window frames.

Are energy efficient windows worth the money?

If you have single pane windows, then almost certainly energy efficient windows are worth the money because according to the U.S. Department of Energy estimates that you’ll save between $126 to $465 a year by replacing single-pane windows in your home.