5988 Mid Rivers Mall Drive #239. St. Peters, MO 63304

We Go Head To Head With St. Louis’ Most Popular Window


And It Isn’t Even Close

When homeowners in the St. Louis area think it might be time to get replacement windows, their first guess might be that there isn’t much difference from one to the next. The truth, however, is that the quality of windows can vary greatly, even among top-of-the-line replacement windows. So, we decided to go head-to-head with the best-selling top-of-the-line window in St. Louis, which, we might add, costs more than ours.

A Fair Comparison

The first thing we had to decide was the components of a fair comparison between one replacement window and another. We decided that the main factors that homeowners consider when making a purchase are:

  • Durability – How long is it expected to last?
  • Functionality How easy is it to use, and does it stay that way over time?
  • Energy Efficiency – How well does it manage heat loss?
  • Installer And Manufacturer Confidence – How long are they willing to cover their product?

With those four things in mind, let’s see how we fared against one of the biggest names in replacement windows.


We begin with a tie. Both our Windows Depot USA of St. Louis and our competitor expect our windows to last a lifetime. While our competitor slips a bunch of caveats in their expectations, their overall claim is that you will never have to purchase another window for as long as you own your home.

We make the same claim, except without all the caveats. We expect our windows to perform much the same 30 years from now as they do today. A lot of that has to do with our designs taking the term “normal wear and tear” as a challenge and have strived to design windows that defy the effects of normal use.


For the purposes of this contest, we are looking exclusively at triple-paned double-hung windows. Double-hung windows have two sashes that can move independently of one another and can both tilt in for easy cleaning.

Our windows are designed with integrated latching mechanisms that will never get crusted up with years of dust and debris. They will be just as easy to operate generations from now as they are the day they are installed. Our track system is so well balanced that you can raise and lower your sashes with a single finger.

Our competitor uses the old fingernail-destroying latches that almost guarantee you’ll stop washing the outside of your windows from the comfort of your home’s interior within a few years. Their track system relies on regular maintenance, and the balance isn’t nearly as precise as ours. It won’t be long before you find yourself muscling your windows up and down as it gets harder and harder to make them move.

Energy Efficiency

Heat loss is the main reason people buy replacement windows for their whole house. They are tired of drafts and frost on the interior glass and really tired of high energy bills, so they add insulation to their walls and replace all their windows. And you know what? It works! The right windows can drop your home’s heat loss by 40%. So let’s dig into this.

Standard double-pane windows have a 90% efficiency against heat loss. Triple-pane windows can take that up to 97%. So, if you ever see frost on the interior side of a triple-pane window, don’t go outside because the temperature would have to be comparable to Antarctica for that to happen.

Inert Insulating Gases

The reason triple-pane windows can achieve such a high level of efficiency is only partly due to their multi-paned structure. The air between each pane acts as an insulator but isn’t dense enough to create those numbers. That’s why replacement window manufacturers fill those spaces with one of two inert gases: argon or krypton.

Argon is the standard gas used in most replacement windows and does a great job of insulating. Krypton is a denser gas than argon and offers even more insulating power, but it is also exceptionally rare and expensive.

Because of the high cost of krypton, many manufacturers have abandoned the product, but we still carry it for homeowners who insist on having the very best available regardless of price.

Seal Leakage

It’s well known in the industry that the standard seal in replacement windows will leak insulating gases at a rate as high as 10% per year. That means that a standard window loses most of its heat loss properties in as little as ten years.

We don’t use standard seals. Our seals are more flexible and can move as the pressure between the panes goes up and down with outside temperatures. This simple but more expensive change, combined with our denser gas, creates an average gas loss of about 1% per year. That means that at 50 years, our windows are outperforming the insulating properties their windows have left at only five years.

Installer And Manufacturer Confidence

While both windows are covered for life, few installers are willing to match that with a promise of their own, and only one of the warranties is riddled with conditional language. Also, with most installers, if your issue is a product defect, you’re on your own when dealing with the manufacturer.

With our ProVia built windows at XteriorPRO / Windows Depot USA of St. Louis, you will never be left in the lurch. First of all, we guarantee our workmanship for life. In fact, if anything at all happens to your windows in the first two years, just give us a call and leave your checkbook in the drawer. We’ve got you covered at zero cost.

After two years, the rare manufacturing defect will only cost you a nominal fee of $75 to cover our labor costs. As for broken glass, the other window simply won’t cover it unless you can prove it is the result of a defect. We, on the other hand, don’t care how it got broken. All we care about is taking care of your problem. We call it our Oops-Proof Warranty.

The Replacement Window Battle Results

While both window systems carry warranties for life, ours doesn’t get bogged down in legal gymnastics to get out of covering defects.

The functionality of each window system sits fairly even on day one, but our windows are designed to keep their full functionality for their entire life. While sure, sticky tracks and latches that won’t move can be considered normal wear and tear, we don’t find that answer acceptable. So, we designed systems that are impervious to normal wear and tear.

Energy efficiency isn’t even a contest. Our competitor’s windows can lose 10% of their insulating capabilities in one year (and every one thereafter) while it takes our windows ten years to reach the same point.

When it comes to having confidence in our products, nobody can beat our simply stated, depreciation-free Lifetime Workmanship Warranty or our manufacturer’s Limited Lifetime Warranty. We don’t count on gotcha language to protect ourselves from warranty work; instead, we count on our product and our to the letter installation process to keep warranty work to a minimum. Our warranty is a promise, not a dare.

And one more thing — we have so much faith in our windows that you can transfer the warranty, unchanged, to the next owner when you move. Our competitor, however, greatly reduces the terms of their warranty when you transfer it to a new owner. If that doesn’t scream lack of faith, what does?

If you think you are ready to put replacement windows on your St. Louis area home and want the best value possible, contact us at XteriorPRO / Windows Depot USA of St. Louis for a free quote. We’ll get your home more energy-efficient than ever and keep it there for life.