How Much Will Costco's Window Replacement Service Actually Save You

When most people think about Costco, the retailer's window replacement service is typically not what comes to mind. However, if you're in the market for new windows, Costco's chosen vendor, Infinity from Marvin, offers varying shapes and sizes, as well as sliding patio, French, or bi-fold glass doors. The vendor even has its own proprietary fiberglass material, Ultrex, which is used in the framing of your window, and a window finisher the company claims is three times thicker than its competitors. But will Costco's window replacement service actually save you money? Well, it's hard to say.

Although a representative from the company will come to your home, give you a quote, and complete the job using their approved products, so will any other independent contractor. Where the cost of labor and materials is concerned, it's difficult to see how Costco (or an authorized contractor) can afford to give you a significant discount over one negotiated with an independent contractor. That said, the jury is still out on whether Costco's window replacement service can save you the same kind of money it saves you on groceries or gas, but it may be worth investigating further.

The best way to know if you are actually getting a deal — between the contractor doing the work and Costco providing the materials — is to actually contact other contractors or big box stores that offer the same service. Be sure to ask for comparable quotes based on the specifications of the window you want installed so that you can get as close to an accurate quote as possible. Keep in mind that Costco's approved vendors are vetted for credentials by the company, so if you go out on your own comparison shopping, you'll want to ensure the independent contractors you source are also accredited professionals. 

You can find professional window replacement experts open to bids on your work online at the American Window and Door Institute (AWDI). If your property was built before 1978, it's possible you'll need a contractor who understands how to navigate the dangers of lead paint on your windowsills or moldings. The Environmental Protection Agency (EPA) has a database of contractors who know how to tell if your home contains lead paint and how to work around it safely. Keep in mind, different contractors have their own rules concerning warranties. Infinity from Marvin offers a special 10/20 limited warranty covering your fiberglass window and finish for 10 years, while insulating glass with stainless steel spacers is covered under a 20-year manufacturer's warranty.

Often the best way to learn is through others' mistakes, and that includes whether Costco's window replacement service is a good deal. Some customers have taken to Reddit regarding their experiences with Costco-related installations. Although many of these experiences concerned HVAC systems, flooring, and kitchen countertops, the discussion offers a general expectation of the value of Costco's service. One Reddit user cited issues working with their contractor, overbilling, and no support from Costco throughout the process. In response, another Redditor recounted a similar experience, having paid market rate or more for a lackluster job.

One Reddit user noted that they were quoted $30,000 for a kitchen countertop job with a 10% Costco rebate card, only for the contractor to offer a discounted (though still high) rate if Costco was left out of the deal. The same user also recounted an incident regarding HVAC installation. While not specific to window replacement installation, these experiences may provide some insight — or more importantly, perspective — when thinking about how much going through Costco might save you. Based on these examples, it may not be too much. Of course, you'll have to do your own research to be sure. Otherwise, play it safe and stick to the items professional interior designers purchase at the retailer and these home products you should be buying at Costco.