The National Fenestration Rating Council (NFRC) tests all windows, doors and skylights sold in the United States for energy efficiency. All windows, doors and skylights must go through an 11-step product certification process. All windows, doors and skylights are tested and certified by an NFRC-accredited simulation lab and test lab.

Since 1936, the American Architectural Manufacturers Association has stood as a strong advocate for manufacturers and professionals in the fenestration industry. The AAMA is dedicated to the promotion of quality window, door, curtain wall, storefront, and skylight products. In 1962, the AAMA Product Certification Gold Label told customers that a sample of the product has been verified through independent laboratory testing and follow-up on-site inspections of the window manufacturer’s production line. All wood, vinyl, fiberglass, metal, and composite materials used in the manufacturing of windows, doors, skylights, and storefronts must meet strict AAMA test standards. On January 1, 2020, the AAMA and the Insulated Glass Manufacturers Association (IGMA) joined forces to form the Fenestration and Glazing Industry Alliance (FGIA). Testing performed by the NFRC and the AAMA proves conclusively that fiberglass windows, with a limited 10-year frame warranty, are nothing more than an overpriced alternative when compared to high-quality vinyl replacement windows with a lifetime limited transferable warranty.

NO! While all of the window frames and sashes are made from PVC, every manufacturer uses different frame extrusion designs, grades of vinyl, spacer systems, and other components. Vinyl windows are like automobiles. They may look alike but every vinyl window is different in vinyl quality, durability, performance, design and warranty. Fiberglass and composite window dealers use scare tactics against vinyl windows when promoting their high-priced windows. The truth is our professionally-installed vinyl windows perform equal to or better than higher-priced fiberglass and composite windows at half the price!

No they are not! All windows, doors, and skylights are subjected to the exact same NFRC heat loss/gain and air leakage tests. Certified NFRC test results show that fiberglass windows with basic Low-E glass do not outperform vinyl windows. In many cases, affordably-priced vinyl windows with basic Low-E outperform fiberglass and composite windows that sell for approximately $2,500.00+ per window. Energy efficiency and air leakage tests conducted on all windows by the NFRC include the entire window and frame.

PROFIT! If you tell a big enough lie, and keep repeating it, it becomes the truth! Window manufacturers spend millions of dollars every year brainwashing consumers about their overpriced fiberglass and composite windows being stronger than vinyl. The fact remains all fiberglass, wood, and vinyl window frame materials along with all other window parts must be tested and approved by the AAMA. Energy testing is done by the NFRC. High-quality vinyl replacement windows are subjected to the exact same tests as fiberglass, wood, and composite windows. Tests have proven that fiberglass and composite windows do not perform better than high-quality vinyl windows.

No. Fiberglass frames and sashes are mechanically fastened with screws, staples, or glue. Clear silicone caulking is also used to seal the window frames and sashes from leaking water. Many fiberglass windows have a limited 10-year frame/20-year glass warranty. Frame warping, bowing, and twisting are excluded on fiberglass warranties. Our Platinum Series vinyl windows with Sunshield® vinyl have a fully transferable lifetime limited warranty and cost less than fiberglass windows.

U-factor: Measures how well a window or door keeps heat from escaping from inside the home. Look for low numbers. Range: 0.20- 0.29. Energy Star qualified windows must have a U-factor rating of .22 or lower as of 10/23/23.

Solar Heat Gain Coefficient: Measures how well a window or door resists heat gain from the sun. Look for low numbers.

Range: 0.17 or lower

Air Leakage: Measures how much air will enter the home through a window or door. Look for a low number.

Range: ≤ 0.3. cfm

Visible Transmittance: Measures how well a window will effectively light your home with natural daylight. Look for high numbers. Range: 0-1.

Up to $1,800.00 per window opening on double-hung and slider windows, more on casement-style windows.

Approximately $3,000.00 to $4,000.00 on a six-foot patio door.

In Pennsylvania, the dealer is responsible. If the problem is with the installation, the dealer needs to correct the problem. If the problem is a defective product, the manufacturer’s warranty should cover replacement. In any event, the dealer should be contacted first. An added fact is the labor warranties are limited to one year from the date of installation.

Both systems use “Warm Edge Technology”. The main difference is Super Spacer is a soft, flexible silicone foam material while the Intercept spacer is a metal system. Both systems allow the glass to deflect with temperature changes. The Super Spacer system improves energy efficiency only slightly better than the metal spacer and costs more.

Both Argon and Krypton are odorless, colorless, non-toxic inert gases that are used to increase the insulation and energy efficiency inside I.G. units. Argon gas is cheaper and more plentiful, while Krypton gas costs more and is the better insulator. Krypton gas is used almost exclusively inside triple-pane glass windows. Krypton gas is much heavier than Argon and costs 30 times more. Ukraine supplies 40% of Krypton gas globally. Two Ukraine air separation firms were closed due to Russian military operations in the region. Krypton gas is in short supply to the window industry.

Clear glass vinyl windows have a U-factor rating of .46 and higher. They are less efficient than vinyl windows with Low-E Argon glass that have a U-factor rating of .29. The rate of heat loss on clear glass windows is 17 points higher than windows with Low-E Argon glass packages. The cost of Low-E Argon glass adds about $20.00 to the average double hung or slider window. Money saved on clear glass windows is quickly spent on higher energy bills.

Yes, it is. Energy Star is a US Environmental Protection Agency voluntary program. In 2016, the EPA changed the Energy Star U-factor requirements on windows from .30 to .27. As of October 23, 2023 the Energy Star Certification criteria for windows drops from a U-factor rating of 0.27 to 0.22, requiring replacement windows to have triple-pane glass in order to meet the new Energy Star 7.0 criteria.

The Energy Star label tells you that a window or door is Energy Star Certified. The NFRC label lets you compare independent ratings of energy-efficient windows and doors between different window and door manufacturers. What you will find is that higher-priced fiberglass and composite replacement windows are no more energy efficient than vinyl replacement windows. Many window manufacturers have omitted the NFRC test results for their windows on their website. We believe this is done intentionally since the NFRC test results prove fiberglass window performance is no better than vinyl windows.

No, but it should be. Clear glass (no Low-E) is still available on all windows and doors made today and sold by budget window dealers. House flippers looking for cheap windows use clear glass windows. We find it interesting with all the concern over global warming that the federal government has not banned window manufacturers from selling windows and doors without basic Low-E Argon glass. Our question is why?

Inflation! Since 1995 not one window was ever sold for the advertised price of $189.00. You have a better chance of seeing Bigfoot in the woods before ever having any window installed for $189.00.

Tempered glass is annealed glass which has been heated to a temperature near its softening point and forced to cool rapidly under carefully controlled conditions. The heat-treating process produces additional strength, resistance to thermal stress, and impact resistance. Tempered glass is standard on all entry and patio doors sold in the United States. Windows located inside bathrooms, other wet locations, on decks, in stairwells, along sidewalks, and next to entry doors are required to have tempered glass. Windows with the edge of glass less than 18” from the floor are also required to have tempered glass. Tempered glass is designed not to break in the event someone would accidentally fall into the window. Tempered glass cannot be cut to size like regular glass. It is made only when a window’s location requires the glass to be tempered. Tempered glass is sold by the square foot and increases the price of replacement windows. There is a large window dealer located in Pittsburgh that routinely omits tempered glass on bathroom windows from their quotes in order to keep the price down. Please note tempered glass is required on bathroom windows with tubs and showers when they located 60” or less from the water’s edge! Click the link marked Safety for additional information.

The windows the people stand on have tempered glass in the sashes. This is never revealed. Tempered glass easily supports the weight of an adult without breaking. Tempered glass adds about $200.00 to a window’s cost. Tempered glass is a safety code requirement on all bathroom windows, doors, and patio doors sold in the United States. We find it interesting that this company uses tempered glass in their advertising, then omits tempered glass on bathroom windows (a safety code requirement) from the written estimates we have seen.

By leaving tempered glass off the bathroom window(s), the dealer ensures their price will be lower than other window dealers bidding on the same job. This is a deliberate safety code violation and needs to stop. Refer to our Safety page on where and when tempered safety glass is required.

Yes, if there is an accident resulting in an injury or death from a person falling into the window, the dealer is legally responsible for all injuries. Budget window dealers care more about selling windows and less about safety codes.

All wet locations like bathrooms, next to entry doors, on stairways and step landings. Refer to our Safety page for detailed information on tempered glass safety codes.

No. The higher price is due to the higher mark-up from the dealer. You are paying for the name. If you take the time to compare fiberglass to vinyl window performance (U-factor rating), Marvin Infinity double hung with Low-E Argon glass has a U-factor of .28 and SHGC of .32. Our Platinum Series double hung has a U-factor rating of .27 and a SHGC of .21. The Marvin Infinity window sells for $2,500.00+ while our Platinum Series vinyl window is about half the price. Our lifetime limited warranty transfers 100% in-kind to the next homeowner. Upon property transfer, the Marvin Infinity warranty is limited to 10/20 years. Fiberglass dealers continue to spread unsubstantiated claims that fiberglass is superior to vinyl.  The certified NFRC test results and weak fiberglass warranty expose the truth. When you compare energy efficiency, warranty and price, our Platinum Series vinyl windows are equal to or better than fiberglass windows. Those are the facts.

Not likely. Vinyl window manufacturers looked into fiberglass windows back in the 1990’s. The issue with fiberglass is, and always will be, with how the frames and sashes are mechanically fastened with screws, then sealed with clear caulking, leaving the possibility for water leaks if the caulking would fail. Some fiberglass frames are chemically bonded (glued).  Pella fiberglass windows have staples, screws, and glue holding them together. Fiberglass is a strong material except it cannot be heat welded at the corners and must be held together with mechanical fasteners. The reason for the short warranty period is to limit the manufacturer’s liability. All Pella product warranties now come with a “Class Action Waiver”.

Customers purchasing Pella products waive their right to have a court or jury decide disputes. Customers waive all rights to proceed as a member or representative of a class action, including class arbitration regarding disputes arising out of or related to Pella products. Customers must contact Pella within 90 calendar days of the date of purchase to opt out of the Class Action Waiver or lose the right to be a part of any future class action settlement involving Pella products. Customers buying installed windows do not get a copy of the product warranty until after the product is installed. Lead times can vary from 4 to 12 weeks or longer. Pella gives their customers 90 calendar days from the date of purchase to opt out of the class action waiver.

Yes.  As of May 7, 2019, Andersen also gives their customer 90 days to opt out of their Dispute Resolution Process. Renewal by Andersen customers have a one-year period to opt out of the class action waiver.

Putting it politely, weak!  Warping, bowing, twisting, and thermal efficiency are excluded from the fiberglass window warranty we read. Glazing has a 20-year warranty. Fiberglass windows for the most part offer a limited warranty. Property owner transfers are limited to 10/20-year term. Our Platinum Series window with SunShield® vinyl has a fully transferable Lifetime Limited warranty. Fiberglass and composite windows claim to be stronger than vinyl windows. The short warranty and the high price expose the truth.