20 Best Window Companies in Mercer Island, WA (2025 Reviews)

How Installing Energy-Efficient Windows in Mercer Island Saves You Money

When you upgrade to energy-efficient windows, you may see a few benefits, such as:

• Protect your valuables: The low-emissivity coatings on many Energy Star certified windows help reduce damage from the sun's UV rays to your floors, carpets and furniture.
• Decrease your carbon footprint: You can reduce your indirect greenhouse gas emissions by about 12% once you install Energy Star certified windows. In Mercer Island, that’s about 271 pounds per year on average.
• Protect your investment: If your home is on the older side, your windows are most likely in need of replacement. Upgrading your windows can make your home more comfortable and also help raise the value of your house if you decide to sell.
• Save money on power bills: Because energy-efficient windows reduce the amount of energy used to heat or cool your home, they can help you save around $366 annually on your energy bills in Mercer Island.

Estimated Cost of Window Replacement in Mercer Island

Windows come in varying purposes, styles and shapes, so costs and services will vary remarkably based on several factors. Below, we go over the typical cost and services that you’ll find from window replacement companies.

How Much Do New Windows Cost?

On average, homeowners in Mercer Island can anticipate that most window installations will cost between $250 and $1,200, with the most common installations sitting at about $600. But costs vary considerably based on the size of your home, complexity of the installation, your location and the quality of the company you choose. Many window companies also offer door installations, which have a higher price tag.

Whether or not you pick energy-efficient windows is another factor that will affect the cost. These will typically cost more than other windows, but on the other hand, you can save about $366 a year on your energy bills in Mercer Island.

The cost of your window installation will also vary based on the kind of material you choose for the frames. Wood windows are generally the most expensive, though it depends on whether they are completely wood or clad with aluminum or vinyl. Fiberglass windows also tend to be somewhat more expensive than vinyl, but they are more efficient.

What Services do Window Installers Offer?

There are typically two types of window installation services: full-frame and pocket installations.

A full-frame installation replaces the total window, including the sill, frame, trim and the window panes. As this kind of installation requires more time, it will cost more than a pocket installation. Pocket installations are simpler and won’t carry as large a bill because they involve merely replacing the window within its existing frame. But if the frame has any damage, you may have to get a full-frame installation instead.

Your window installation company will be able to help you choose what’s best for your needs. In Mercer Island, the decision will mostly be based on the age of your home and if there’s any damage. Wood can decay if it’s not properly maintained over the years, so it’s a good idea to have a professional check on your frames and window sills.

How We Choose the Best Window Installers in Mercer Island

EcoWatch differs from other reviewers because we look at these companies through a sustainability lens. Along with energy efficiency, we reviewed each installer and assigned rankings using the following methodology:

Service Area

Because this is a guide for Mercer Island, we paid more attention to companies that cover the city. There are other reputable providers that didn’t make the list because they wouldn’t be able to serve homeowners in Mercer Island.

Work Quality

We’re certain that you’re looking for professionals who do a great job installing windows. We’ve vetted each company in our guide to make sure its technicians are well-qualified and that the company has received plenty of positive customer feedback to vouch for its service.

Customer Reviews

We analyzed trends in recent customer feedback to determine the companies with the most consistent customer satisfaction. Customer satisfaction may be the most important factor, as it reflects the quality of services across nearly every category, including quality of parts, warranty, quality of installation, professionalism, cost and more.

Cost

Cheaper windows certainly don’t mean better windows, but we know many of our readers want to keep costs low when possible. When analyzing the prices of providers, we awarded higher points to companies with reasonable prices and accessible financing rather than “cheaper” services.

Warranty

As discussed, windows are a substantial investment, so you’ll want to be certain that investment is well protected. Window installation companies that provide lengthy warranties for products, parts and labor rank higher with EcoWatch.

Years of Experience

Last but not least, we like to see companies that have a good track record in the industry. Window installers that have more experience earn higher rankings by our standards. We like to see at least ten years of experience.