20 Best Window Companies in Diamond Bar, CA (2025 Reviews)

How Installing Energy-Efficient Windows in Diamond Bar Saves You Money

By switching to energy-efficient windows, you and your family can benefit in several ways, including:

• Protect your investment: Upgrading your windows is an important part of maintaining your property and its real estate value, especially if your home is on the older side.
• Protect your valuables from fading: When you switch to energy-efficient windows with low-emissivity coatings, your floors, carpets and furniture will fade less due to their ability to filter out harmful UV rays.
• Decrease your carbon footprint: By using less energy once switching to energy-efficient windows, you’ll also be decreasing your carbon dioxide emissions by about 12%, according to Energy Star.
• Save on power bills: According to the Department of Energy, heat gained or lost through windows accounts for around 25-30% of household energy use. Switching to energy-efficient models can help lower that number, therefore saving you about 12% more on your bills.

Estimated Cost of Window Replacement in Diamond Bar

When researching window installation, each company provides different services and costs. Let’s look at some average costs and services.

How Much Do New Windows Cost?

Typically, Diamond Bar homeowners can expect their window replacements to range from $250 to $1,200. The average cost sits at about $600. This is because the cost of window installations depend on several factors specific to your home, like the size, material and number of windows you need to install, as well as the location of your property.

It’s important to bear in mind that windows with higher efficiency may cost more initially but can save you hundreds of dollars by lowering your energy bills. Investing in Energy Star certified windows can save Diamond Bar homeowners $509+ a year when replacing single-pane windows.

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

What Services do Window Installers Offer?

Generally, there are two kinds of window installation services companies offer: full-frame and pocket installations.

A full-frame installation is a total window replacement. This service involves removing the old window, the windowsill, and the exterior and interior trim. It can also involve other materials, like insulation and drip edges, which raise the total cost of the project. It’s also worth noting that it’s not uncommon for homeowners to have to touch up the paint around the window after a full-frame installation. Pocket installations are simpler and won’t cost as much because they entail merely replacing the window within its existing frame. But if the frame has any damage, you may need a full-frame installation instead.

Your window installation company will be able to help you figure out what’s best for your needs. In Diamond Bar, the decision will mostly be based on how old your home is and if there’s any damage. Wood can decay if it’s not maintained properly over the years, so it’s good to have a professional evaluate your frames and window sills.

How We Choose the Best Window Installers in Diamond Bar

In our search to find the most reliable, eco-friendly window installers in Diamond Bar, EcoWatch examined dozens of companies before landing on these. We have assessed the best window replacement companies in Diamond Bar mostly based on their energy efficient offerings, as it’s what’s best for the environment and for you as a homeowner. Energy-efficient windows have been shown to reduce your electricity bills by hundreds of dollars. Along with energy efficiency, our rating methodology considers the following factors:

Service Area

This one is pretty self-explanatory, but we’ve chosen to highlight window installers that serve the Diamond Bar area so you can find a quality window installation company near you.

Work Quality

We’re willing to bet 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 contractors 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 online reviews to find the companies with the most customer satisfaction, weighted by sample size. Customer satisfaction may be the factor we place the most value on, as it indicates the quality of services across most other categories, including warranty, quality of installation, professionalism, cost, quality of parts and more.

Cost

This one is a give-and-take: as with most services, cheap window companies may not provide the highest quality service. On the other hand, we want to ensure we’re highlighting companies that offer a variety of price and financing options so they’re accessible to most homeowners.

Warranty

Protecting your investment in new windows is important. For that reason, window installation companies that have 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 years of experience earn higher rankings by our standards. We like to see at least ten years of experience.