How Long Do Impact Windows Last? Lifespan and Glass Replacement

How long do impact windows last is a question manufacturers deliberately avoid answering. The InterNACHI Standard Estimated Life Expectancy chart is the closest thing the industry has to a published benchmark. It puts aluminum and aluminum-clad windows at 15 to 20 years. Vinyl and fiberglass windows are rated at 20 to 40 years. InterNACHI notes these figures are a general guideline, not a guarantee. Life expectancy varies with usage, weather, installation quality, and maintenance. Those ranges were not written for impact-rated products in high-velocity hurricane zones (HVHZ). Salt air, UV radiation, and annual storm loading accelerate every failure mode in HVHZ. Florida homes on the Intracoastal Waterway or within 1 mile of the coast see hardware and finish degradation 2 to 3 times faster than inland properties. South Florida's climate adds about 10 to 15 percent more annual UV exposure than the national average. That extra UV accelerates vinyl oxidation and sealant breakdown. Treat manufacturer warranties as a floor, not a ceiling. Inspect every window after 10 years regardless of frame material.

5 distinct components can trigger a replacement decision, and each fails on its own timeline. The insulated glass unit (IGU) seal is almost always the first to go. When the seal breaks, argon gas (used to improve thermal performance) escapes, and humid South Florida air rushes in. PGT's condensation guide is direct: if condensation appears between the two layers of glass in an insulated window, the airtight seal has probably been broken and the glass will need to be replaced. Seal failure is visible as persistent fogging or haze between the panes that does not wipe away. Delamination of the laminated interlayer, the clear PVB or SentryGlas film bonded between the glass lites, is the second failure mode. It appears as a milky or bubbling discoloration at the edges of the panel, usually after 10 or more years of UV exposure. Stress cracks, which originate at the edge of the glass without any impact, are a third mode and are typically tied to frame distortion or improper installation. Corrosion of aluminum frames and hardware is the fourth, most common in coastal zip codes from Miami Beach to Palm Beach. Finally, worn weatherstripping and failed sash locks reduce both air infiltration performance and, in some cases, wind-load compliance.

Understanding how long do impact windows last requires reading warranty documents carefully. Coverage periods vary by component, not by the window as a whole. PGT's Replacement Product Lifetime Limited Warranty is effective September 1, 2026. It covers products made after that date. The frame and panel material are protected for as long as the original owner-occupant owns and lives in the home. IGU seal failure causing fogged, dusty, or outgassed glass is covered for 20 years. Laminated or impact IGU delamination is covered for 10 years. Stress cracks are covered for just 1 year. PGT provides skilled labor or pays shipping on claims made within 2 years of delivery in its service territory, which includes Florida. After 2 years, the owner pays inspection, labor, disposal, and shipping. PGT's warranty excludes glass breakage other than stress cracks. It also excludes normal wear, corrosion from abnormal environments, and lack of maintenance. Power washing and the application of tints, films, or abrasive cleaners are excluded as well. For a deeper look at CWS terms, our CWS windows warranty guide covers aluminum and vinyl coverage side by side.

SafeGuard's preferred premium line is Eco Novo, manufactured in Medley, Florida. Eco Novo features 9/16-inch laminated glass. It carries an exclusive lifetime warranty through SafeGuard. That level of coverage is not available through standard retail channels. Eco Novo is US-made and built to Florida's exacting HVHZ standards. Its warranty removes the expiration date entirely for covered defects. That makes it a strong answer to how long do impact windows last. You can read a full product breakdown in our Eco Novo impact windows review. The CWS Vinyl Window and Door Lifetime Limited Warranty offers a middle-ground option. The vinyl frame is warranted for 30 years. The laminated glass unit is covered for 20 years against delamination. Stress cracks are covered for 12 months. CWS ships a replacement panel to the original owner, but labor costs are not included. Whatever brand you choose, SafeGuard's callback rate runs under 3%. That is an order of magnitude lower than the typical South Florida general contractor. It means installations are done right the first time and warranty claims are rare.

Florida's Existing Building Code Section 401.3 and 402.1 permits like-for-like repairs provided no dangerous or unsafe condition is created and the building is not made less conforming than before. In practice, that means a replacement IGU must match the approved glass makeup listed on the original product's Notice of Acceptance (NOA) or Florida Product Approval. For example, Miami-Dade NOA 25-0520.01 for the PGT SH5500 series lists allowable glass types 5 through 16, all 7/8-inch nominal insulating units pairing a laminated lite with a .090-inch Trosifol PVB or SentryGlas interlayer by Kuraray and an outer annealed or tempered lite. Types that use an annealed outer lite may not be used in the HVHZ above 30 feet. If the replacement glass makeup is not on the approval list, a full window replacement is required, and the new unit must meet Chapter 16 of the Florida Building Code for wind load. Replacement windows must also be permitted and inspected. Choosing between glass swap and full replacement typically comes down to 3 factors: whether the frame is structurally sound, whether an approved glass makeup is available from the original manufacturer, and whether the total installed cost of a new IGU (glass plus labor) approaches the cost of a full impact windows installation with updated hardware and a new warranty clock.

7 maintenance habits have the largest impact on how long do impact windows last in South Florida's salt-air environment. PGT's warranty excludes damage from power washing, brick wash, acids, salts, abrasive cleaners, and solvents. It also excludes damage from failing to open and close operable panels monthly. That last point surprises many homeowners. PGT states that panels should be opened and closed monthly to keep seals and hardware in working condition. Rinse frames with fresh water after salt exposure. Lubricate tracks and hinges twice a year with a silicone-based product. Inspect sealant (caulk) at the perimeter annually to keep the frame-to-wall joint watertight. Never apply tints or aftermarket films. PGT's warranty excludes all such applications. An unapproved film can change the solar heat gain enough to cause thermal stress cracks. If your windows are approaching 10 years, check whether you can verify their impact rating using the etching on the glass edge or the label on the frame. Verifying the original NOA number helps you source the correct replacement IGU if a seal fails. The Florida DBPR contractor lookup tool lets you confirm that whoever performs any replacement work holds an active Florida license. That is a basic but critical check before signing any contract.

3 scenarios almost always justify full window replacement rather than a glass swap. First, if the frame shows corrosion past the finish coat, the structural integrity is compromised. Pitting into the extrusion itself means no IGU replacement will restore code compliance. Second, if the existing window was installed before Miami-Dade adopted current HVHZ standards, it likely lacks a valid NOA. No approved glass makeup exists for it in that case. The entire unit must be replaced with a product that meets current Chapter 16 requirements. Third, if a homeowner is planning to refinance or sell within 2 to 3 years, new units reset the warranty clock. New units also provide documentation that satisfies both underwriters and buyers. Homes in Broward County and Miami-Dade County that replaced windows more than 15 years ago should budget for this proactively. Our best hurricane impact windows buying guide compares current top-performing products by frame material, glass makeup, and approval status. It helps you choose a replacement that maximizes both protection and resale value. For a side-by-side look at frame options, see our vinyl vs. aluminum windows comparison.