The newly published ANSI Z97.1-2026 marks the first substantive revision of the U.S. safety glazing standard in over ten years — and for the first time, vacuum insulating glass falls formally within its scope. Here's what architects, fabricators, and window manufacturers need to know before spec season.
A Ten-Year Wait Ends
The American National Standards Institute has published ANSI Z97.1-2026, the national standard specifying safety performance requirements and testing methods for glazing materials used in buildings to reduce injury risk. The update revises the 2015 edition (reaffirmed in 2020), and for residential door and window manufacturers, the 2026 update represents the first significant change in the standard's technical content in over a decade, following a 2020 edition that reaffirmed 2015 criteria.
For a document that governs how virtually every piece of tempered, laminated, and specialty glass in North American buildings gets tested and marked, that's a long dormant period. The 2026 revision closes gaps that have been widening as VIG, chemically strengthened glass, and next-generation coatings have moved from lab curiosities to mainstream specifications.
VIG Is Finally Inside the Tent
The headline change: vacuum insulating glass is now formally recognized within the safety glazing standard. Vacuum Insulating Glazing (VIG) is now included within the standard's scope, and a VIG impact and rating protocol has been added. The standard now defines VIG as a manufactured assembly of at least two lites of glass, hermetically sealed with a narrow, "highly evacuated" space maintained by spacers (pillars).
That inclusion matters because VIG products from LuxWall, AGC, and other manufacturers have been landing in commercial curtain wall specifications with double-pane profiles and triple-pane U-values — but until now, safety compliance for VIG had been a gray zone that specifiers had to reason through by analogy.
Industry veterans have been pushing for this for years. "Great to see the addition of VIG into the ANSI standard, as it has been a point of debate for over a decade," says Dave Cooper, a consultant and president of Fenestration Consulting Services LLC. "No real substance, other than inclusion in the various tables, but it's a start."
The practical caveat: most fail to realize that VIG is tested the same as a monolithic piece of glass or, if part of a laminated assembly, as a laminated product. And tempered VIG has its own quirks under the drop-bag test because of edge-seal coupling. Specifiers writing VIG into hazardous-location openings (doors, sidelites, low glazing near walking surfaces) now have a defensible standard to cite — even if the protocol itself will keep evolving.
The Other Technical Changes That Will Hit Submittals
Beyond VIG, the 2026 edition consolidates and modernizes several test references:
- Five separate weathering standards (D1435, D2565, D4459, G155, ISO 4892-2) were consolidated into a single umbrella practice: ASTM C1900
- ASTM E903 was added as an alternate visible light transmittance measurement method
- Bake/boil thermal testing and result evaluation are now delegated to ASTM C1914
- Chemically strengthened glass is addressed more clearly, including an exclusion clarification and an engineering-based exception
- More flexibility was provided to impact tests and classification
The weathering consolidation is more than housekeeping. Testing labs and interlayer manufacturers had been navigating five overlapping standards; ASTM C1900 gives everyone a single referenced procedure, which should tighten inter-lab reproducibility and shrink the compliance paperwork.
What Manufacturers Have to Do Differently
Marking obligations have been sharpened. Every piece of safety glazing must be legibly marked with the supplier's name, the "ANSI Z97.1-2026" designation, the size classification and the drop height class. Stock sheets of laminated glass must be marked by the original manufacturer, while cut-to-size laminated glass must be marked by the company producing the finished product. Tempered glass must be marked by the company producing the finished cut-to-size product. For specialty applications, materials intended for "Indoor Use Only" must be explicitly marked as such.
For fabricators, that clarifies chain-of-custody responsibilities that have historically been fuzzy — particularly on laminated stock that gets cut down after leaving the primary manufacturer. Expect QC systems and etch/print stations to be updated over the next several months to reflect the new designation string.
Why This Matters for Spec Writers Right Now
ANSI Z97.1 is referenced by building codes and by federal 16 CFR 1201 pathway determinations. When the underlying standard changes, downstream spec language eventually has to follow. Three practical implications for architects and building envelope consultants:
- VIG specifications can now cite an ANSI-recognized safety pathway rather than relying on manufacturer-specific test data alone
- Weathering language in Division 08 sections should transition to ASTM C1900 references for laminated and organic-coated products
- Submittal reviews should verify that new safety glazing carries the updated "ANSI Z97.1-2026" designation, not the 2015/2020 marking, on projects going out to bid in late 2026 and beyond
As Julia Schimmelpenningh, chair of Accredited Standards Committee (ASC) Z97, put it: "We are proud to deliver a standard that supports durable safety glazing products while maintaining the high level of proven performance that has been in place for many decades". Translation: the safety floor hasn't moved, but the doorway just got wider for the next generation of high-performance glazing to walk through it.