Editor’s note
This fortnight was thin on the documents a US specifier actually writes into a spec. No ASTM work-item ballot, no new ICC / IBC / IECC text, no NFPA 285 revision, no Miami-Dade Notice of Acceptance, and no California Title 24 envelope note appeared in the public record between 16 and 30 August. No manufacturer recall of architectural glass, structural silicone or insulating-glass units was posted either. What the window did produce is listed below, United States first. Two items sit a few days before 16 August — FGIA’s acoustics technical information report (10–11 August) and a USGlass curtain-wall retrofit note (6 August) — because both are usable on a current specification. NAFS-26 itself was published in June; it is here because Window + Door ran the specifier explainer on 27 August, ahead of GlassBuild. International project notes come after the US block, and only where the detailing transfers (solar geometry; podium stick versus unitized high-insulation framing).
United States
1. FGIA republishes AAMA TIR-A1 on acoustics — STC is not OITC
On 10 August the Fenestration and Glazing Industry Alliance released an updated AAMA TIR-A1, Acoustical Performance of Exterior Fenestration Products, last revised in 2015. Building Enclosure carried the same notice on 11 August. The report describes how sound is transmitted, measured and controlled, and it differentiates Sound Transmission Class (STC) from Outdoor-Indoor Transmission Class (OITC) and when each classification is appropriate. FGIA says the update consolidates IGMA TM-6000 and the previous AAMA TIR-A1 into one reference, with input from the Residential, Architectural and Glass Products Councils. Member price $25; non-member $70.
Why it matters. Curtain-wall acoustics are specified against outdoor noise, not party-wall speech. OITC weights low-frequency traffic and aircraft better than STC; quoting only STC on a street or airport elevation is a common mismatch. The report is a TIR, not a test method — it does not replace ASTM E90 / E1332 laboratory work or a project mockup — but it is the document to hand a design team that has written “STC 35” on a curtain wall that faces a freeway. It also pairs with Facade Tectonics session 7A in Pittsburgh (item 6), which includes “Demystifying Acoustic Performance in Curtain Wall.”
Sources: FGIA, 10 August 2026; Building Enclosure, 11 August 2026.
2. NAFS-26 makes the secondary designator mandatory on US labels
Window + Door published Aaron Blom’s explainer on 27 August. The 2026 edition of AAMA/WDMA/CSA 101/I.S.2/A440 (NAFS-26) was released in June by FGIA, WDMA and CSA. The change that matters for labels is this: NAFS-22 (clause 4.6.3.1) allowed an optional secondary designator showing tested positive and negative design pressures, water-penetration resistance test pressure and air-leakage test pressure. NAFS-26 makes those test-pressure values mandatory on US certification labels, except air leakage, which remains optional. FGIA’s June notice states the change was proposed by FEMA after concern about water intrusion in coastal and hurricane-prone regions, including alignment with issues previously raised by the Florida Building Commission. Blom writes that FEMA had prepared code-change proposals for the IRC, IBC and Florida Building Code that could have created an alternate product-approval path; after the NAFS revision, those proposals were not submitted. NAFS-22 is the edition referenced in the 2024 IBC and IRC; NAFS-26 is proposed for the 2027 codes. An equivalency document (testing to one edition versus the other) is expected later this year. Blom is presenting “NAFS-26 | Understanding Key Changes and Impacts on Testing Requirements” on the GlassBuild America main stage on 24 September at 2:20 p.m.
NAFS is a standard for windows, doors and skylights. It is not a curtain-wall test method. Curtain-wall air/water/structural work still lives in AAMA 501 / AAMA 503 and the ASTM E283 / E330 / E331 family.
Why it matters. Mixed envelopes still put punched openings next to curtain wall. Specifiers and building officials will start seeing labels that state the actual tested +DP, −DP and water-test pressure, not only a performance grade. That is the number to check against the project’s ASD design pressure and water-test criterion, especially in HVHZ and other coastal work. Do not write NAFS as the curtain-wall specification; do write it, once adopted in your code edition, for the windows and doors that share the wall.
Sources: Window + Door, 27 August 2026; FGIA, 1 June 2026.
3. Retrofit: VIG in a 1960s curtain wall does not fix the frame
USGlass Insights (6 August) published a conversation with Sarah Sinusas, PE, of Wiss, Janney, Elstner (Connecticut). The US Department of Energy figure cited in the piece: about 2.4 million commercial buildings — roughly 40 percent of the stock — still have single-pane, non-thermally broken fenestration, with a retrofit rate under 1 percent a year. The worked example is a 22-story office with a 1960s curtain wall of 6 mm monolithic clear glass, a 1990s room-side bronze solar-control film, and an exterior wet seal of pre-formed silicone sheets. Structure could not take much added glass weight. Replacing the 6 mm lite with vacuum insulating glass (two 4 mm lites) cut the assembly U-factor from 1.08 to 0.33 Btu/h·ft²·°F — a factor of three — but left the frame’s room-side temperature unchanged. The expressed exterior T-mullion is a continuous thermal path. Adding custom snap-on polyamide extrusions on the interior U-channel, plus insulation under a new room-side mullion cover, brought the assembly to 0.17 Btu/h·ft²·°F and raised interior frame temperature. The vision lites were 6 ft 8 in by 4 ft 8 in; edge and frame effects still dominated. For old pressure-plate walls, the same article notes swapping aluminum pressure plates for polyamide plates as a simpler frame move. Polyamide here is non-structural thermal isolation, held to tight extrusion tolerances (Technoform: at least ±0.05 mm).
Why it matters. Center-of-glass U-factor is not the assembly. A VIG or thin-triple swap that ignores a non-thermally broken aluminum frame leaves condensation risk and a thermal short at every mullion. Specify THERM (or equivalent) on the actual mullion, not a catalog NFRC size; confirm added dead load against existing anchors; and treat interior polyamide covers as a thermal detail, not a finish extra.
Source: USGlass Insights, 6 August 2026.
4. Mobile International Airport: large-missile VS1 on a 28 ft-6 in span
On 19 August Innovation Glass announced that the VS1 curtain walls at Mobile International Airport, Alabama, received Glass Magazine’s 2026 Best Protective Glazing Project award. Glass Magazine’s project write-up (22 July) is the technical source. The 35,000-square-foot facade is a hybrid point-supported system: vertical extruded mullions and cassette glass panels, T-bracketed, with no horizontal framing of a conventional curtain wall — the nominating team says that removes about half the metal. Mullions span 28 ft 6 in with no steel reinforcement. The wall is a large-missile impact VS1, tested to ASTM E1886 / E1996, Wind Zone 4. A performance mockup resisted 169 mph. A pin connection was developed for a segmented radiused wall; Glass Magazine reports more than 30 panels set per day and a flush-glazed exterior with no visible metal. Architects: HOK and FSB Architects. Contract glazier: Metropolitan Glass Co. Curtain-wall engineer/supplier: Innovation Glass.
Why it matters. Hurricane work is usually sold as captured stick or unitized impact curtain wall with a lot of aluminum. This project is a specifier reminder that large-missile + long clear span is a system test (E1886/E1996 plus the mockup wind load), not a glass-only label, and that omitting horizontals shifts the spanning, deflection and glass-cassette design onto the verticals and the T-bracket. Ask for the tested assembly, the 169 mph mockup report, and how replacement panels are set without a sequence.
Sources: Innovation Glass, 19 August 2026; Glass Magazine, 22 July 2026.
5. UT Dallas ECSW: Solarban 70 at VLT 0.64 / SHGC 0.27, shading by orientation
Vitro Architectural Glass (Pittsburgh, 18 August) and Glass Magazine (24 August) reported the envelope of Engineering and Computer Science West at the University of Texas at Dallas, a 200,000-square-foot LEED Gold building by SmithGroup. Triple-silver Solarban 70 is cited at 64 percent VLT and SHGC 0.27. The facade is treated as a layered system, not a single glass spec: east — large overhangs and a calibrated brise-soleil so the commons, labs and terrace can stay highly glazed; west — less vision, limestone in front of lab casework, and electrochromic strips that tint with solar intensity; north and south — fully glazed faculty offices with projecting shade portals of varying depth. Frit, coatings, metal screens, cladding and spandrel are listed as the other layers. SmithGroup used SketchUp and Revit for solar-insolation and daylight studies. Glass fabricator: Tristar Glass. Glazier: Kovach. GC: The Beck Group. Randall Daniel (SmithGroup, Dallas) is the quoted design lead.
Why it matters. High VLT with a low SHGC is only half the specification in a North Texas cooling climate. The transferable move is orientation-specific shading — brise-soleil and electrochromic on the harsh elevations, shade portals on the offices — so the coating is not asked to do geometry’s job. Demand the SHGC/VLT on the actual makeup, NFRC or project THERM as the energy code requires, and a control narrative for the electrochromic zones.
Sources: Vitro Architectural Glass, 18 August 2026; Glass Magazine, 24 August 2026; Design Cost Data, 20 August 2026.
6. Facade Tectonics 2026 World Congress, Pittsburgh — program is public
The Facade Tectonics Institute’s 2026 World Congress is in Pittsburgh, 28 September–2 October (paper presentations 30 September–1 October). Final papers were due 15 August; notice of acceptance is listed for 1 September. Session 7A (Facade Design, 1 October, Richard Green moderating) includes “Demystifying Acoustic Performance in Curtain Wall.” Session 3C (Modeling & Analysis) lists “Embodied Carbon in Curtain Walls” and “Driving Down Envelope Embodied Carbon.” Factory and site tours on 29 September include TAKTL (architectural precast / UHPC) and ZGF’s construction tour of CMU’s Richard King Mellon Hall of Science. Keynotes: James Timberlake (Kieran Timberlake) and Erik Olsen (Transsolar). The hotel block at the Courtyard by Marriott Pittsburgh University Center is listed as extended through Friday 4 September, group rate $149 per night Monday–Friday.
Why it matters. This is the US peer-reviewed facade research meeting of the autumn. Acoustic and embodied-carbon papers are the items most likely to affect curtain-wall specifications written in Q4 2026 and 2027. The TAKTL tour is relevant to UHPC rainscreen specifiers even if the congress itself is glazing-heavy.
Sources: Facade Tectonics 2026 World Congress; Session 7A — Facade Design; Session 3C — Modeling & Analysis.
Rest of world
7. Brisbane: silicone-glazed curtain wall with elliptical anodized-aluminum sunshades
The Architect’s Newspaper (20 August) and Facades+ (21 August) reported the envelope of 205 North Quay, Brisbane, by REX with Hassell and Richards & Spence. REX’s project record: a conventional silicone-glazed curtain wall on a 1.5 m module, color-neutral double glazing at VLT 0.62; copper-anodized aluminum ellipses on the long northwest and southeast faces and extruded fins on the short elevations; the ellipses cut solar transmission 63 percent relative to an unshaded curtain wall. AN adds that digital solar modeling put the oval about two percentage points behind tinted glass and ahead of a conventional triangular shade; each oval is four identical quarter-ellipses screwed together, bolted to a fin at the IGU edge after the curtain wall is up, with a coating that prevents the anodized aluminum from oxidizing. Facade consultant listed by REX: Front (AN also lists BG&E); wind: RWDI.
Why it matters. External shading can carry SHGC performance that would otherwise be bought with dark coatings or a lower vision ratio. For a US specifier the sequence (curtain wall first, then mechanically fixed shades) and the coating against oxidation are the items to take into a high-VLT or subtropical brief.
Sources: The Architect’s Newspaper, 20 August 2026; Facades+, 21 August 2026; REX — 205 North Quay.
8. Prague: unitized high-insulation element facade with perforated-metal shading
Glass Balkan (29 August) reports Rohan City A1, an eight-story office in Karlín, Prague, by AI – DESIGN (Eva Jiřičná and Petr Vágner) for Sekyra Group. The envelope combines a fully glazed modular facade with wavy silver perforated-metal panels for solar shading. Reynaers Aluminium supplied a project-specific ConceptWall 60-HI variant at ground and first floors for large panes and thermal/acoustic performance, and ConceptWall 86-EF-HI — a modular element (unitized) system — on the upper floors. Ventilation is through MasterLine 8 Hidden Vent. Fabricator: OKM Group Brno. The report states that thermal, structural and air–water–wind (AWW) performance were coordinated with the architectural intent. Glass Balkan notes Reynaers as the originating source, with additional reporting of its own.
Why it matters. A current European example of mixing project curtain wall at the podium with unitized high-insulation elements above, plus an open-joint metal rainscreen used as a brise-soleil rather than as the weather line. Demand project-specific U-factor modeling on the actual module, not catalog NFRC sizes, and a tested AWW sequence for the element joints and the perforated overlay.
Source: Glass Balkan, 29 August 2026.
Reference (not new this week / not US)
No ASTM, ICC, IECC, NFPA 285, Miami-Dade or Title 24 envelope publication was found in the public record for 16–30 August 2026. NAFS-26 (item 2) is June, not this fortnight. AAMA TIR-A1 (item 1) is 10–11 August.
UK CWCT Technical Updates currently listed publicly still run through TU27, December 2025 (Clarification of watertightness requirements with reference to dismantling of test specimens). No August 2026 addition was on the public list when this edition was prepared. CWCT is not a US reference standard.
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