Vacuum-glazing warranties are getting longer — and that tells you something

Vacuum glazing has always faced one honest question above all others: the vacuum has to hold for decades, so how long will the seal actually last? The makers can't answer that with a laboratory certificate alone — but they can answer it with their own money, in the length of the warranty they're willing to write. On that measure, the numbers have quietly been climbing.

LandVac: a 25-year warranty in the UK

In June 2025, Vacuum Glazing UK — the UK distributor for LandVac — launched what it billed as the UK’s first 25-year vacuum-glazing warranty ↗. It’s fully transferable and provided at no extra cost, so it survives a change of ownership, and it sits behind a unit whose centre-pane U-value (0.34 W/m²K) is independently certified by ift Rosenheim. The company points to more than a decade of testing, including 22,500 hours under simulated sunlight — roughly 25 years of weathering.

Worth keeping the layers straight: that 25-year figure is the UK distributor’s warranty. LandVac’s standard manufacturer warranty is 15 years, and the glass is rated for a service life well beyond either number. But a distributor putting 25 years in writing, transferable, is a meaningful vote of confidence.

Fineo: up from 15 to 20 years

AGC’s Fineo has moved the other benchmark. Where its cover used to run to 15 years, Fineo now carries a 20-year full product warranty ↗ — among the longest offered directly by a manufacturer, and well clear of the roughly 10-year term that has long been the industry norm. Fineo is made by AGC in Belgium and is the only vacuum glazing carrying a CE mark, so the 20 years is a manufacturer’s guarantee rather than a reseller’s.

Why it matters — and the caveats

The interesting thing isn’t the warranty admin; it’s what the trend implies. The edge seal is the part of a vacuum unit most likely to fail over time, and it’s the part early VIG was quietly criticised for. When two of the biggest names lengthen their guarantees rather than shorten them, they are betting that their seals — tempered low-temperature bonds in LandVac’s case, AGC’s process in Fineo’s — hold up in the field. That’s the most honest signal a buyer gets.

Two caveats before you read too much into a big number. First, a warranty is not a lifespan: makers talk about 25-, even 60-year service lives, but the warranty is the shorter period they’ll stand behind commercially — and the terms (what’s covered, pro-rata or full replacement, visible haze versus outright vacuum loss) matter more than the headline years. Second, check who is backing it: a manufacturer’s warranty and a distributor’s warranty are not the same promise, and a warranty is only ever as good as the company still being around to honour it. Read the document, not the billboard.

We don't sell glazing and aren't affiliated with LandVac, AGC/Fineo or any distributor. This is independent analysis; the LandVac warranty detail comes from Glass Times ↗ and the Fineo figure from AGC's Fineo material ↗.