TOSTEM at a glance: products, EPDs, gaps
TOSTEM is a LIXIL brand best known for precision‑engineered aluminum windows and entrance doors across Asia. The products look great on the page and on the jobsite. The question many specifiers now ask is simple: how much of that catalog is backed by product‑specific EPDs they can actually use on projects racing toward LEED v5 and whole‑life‑carbon targets.
Who TOSTEM is and where they play
TOSTEM sits inside LIXIL and focuses on residential and light commercial fenestration. They design and manufacture aluminum windows, balcony doors, and entrance doors for new build and renovation. Most sales are in Japan and Southeast Asia, with growing international distribution.
What they sell, roughly how much
Product families cover sliding, casement, awning, louvers, and entrance doors, plus interior retrofit lines for double‑glazing. Across regions that translates to several product families and likely hundreds of individual SKUs when sizes, finishes, and glass options are counted. Plenty of variety without drowning teams in micro‑variants.
EPD coverage today
LIXIL reports a total of 54 EPDs across its brands as of March 2025, including International EPDs for 18 GROHE product groups that span 738 SKUs, and SuMPO EPDs in Japan for two sash windows and for its low‑carbon recycled aluminum profiles branded PremiAL (LIXIL, 2025). PremiAL’s verified footprint is 7.1 kg CO2e per kilogram for standard lots and as low as 2.9 kg CO2e per kilogram for the R100 grade, reflecting about 50 to 80 percent reductions versus new‑ingot aluminum depending on grade (LIXIL, 2025). That is meaningful upstream carbon relief for window frames.
From a specifier’s view outside Japan, publicly listed, product‑specific EPDs for TOSTEM windows and doors remain limited. LIXIL’s plumbing and ceramics lines have multiple verified EPDs available in Western operator libraries, yet fenestration is still catching up.
Why that gap matters commercially now
LEED v5 was ratified in March 2025 and pushes whole‑life‑carbon accounting deeper into design decisions. Teams without product‑specific EPDs often must use conservative defaults that add a hidden “penalty” in project carbon math, which can tip a shortlist. Buildings and construction are still responsible for roughly one third of global CO2 emissions, so transparency at the product level keeps moving from nice‑to‑have to table stakes (UNEP Global Status Report, 2025).
Likely best sellers without easy EPDs
TOSTEM’s core window lines, such as sliding and casement systems widely promoted for export, appear not to have readily accessible EPDs in US or EU operator libraries as of late 2025. That means on projects where EPDs are preferred or required, a TOSTEM unit can be swapped for a like‑for‑like competitor that shows verified numbers.
Who they meet in the spec ring
Common rivals on international projects include YKK AP, Kawneer, Schüco, and Reynaers. Several of these competitors publish verified EPDs for storefronts, curtain walls, and window systems through recognized operators. For example, Kawneer lists UL‑verified EPDs for multiple framing and curtain wall systems on its transparency page, and Reynaers states it offers 19 generic EPDs covering 67 product variants, which helps design teams document faster during tender phases (Reynaers, 2025).
A quick win playbook for TOSTEM teams
Think of the PCR as the rulebook of Monopoly. Pick the rulebook your buyers already use. The new Fenestration Assemblies PCR is gaining traction for complete window assemblies, which simplifies credit documentation across markets. Combine that with existing, verified data for PremiAL to anchor A1 to A3 and tighten the upstream variance. Then collect a clean year of plant data for assembly, coatings, and packaging. Publish through a program operator your target market prefers. In Europe that is often IBU or the International EPD System. In North America many teams look for UL‑verified records.
The heavy lift is data wrangling, not modeling. A white‑glove partner that extracts utility bills, alloy recipes, scrap returns, and production logs from the factory floor with minimal disruption will save months and avoid teh six‑email chases that stall projects.
Where TOSTEM is leaning in on sustainability
TOSTEM highlights a plan aligned with LIXIL’s Environmental Vision 2050 and a push toward recycled aluminum, including a pathway to 100 percent recycled content by 2030 for certain billets. Their sustainability overview is a useful starting point for sales and spec teams who need credible talking points (TOSTEM Sustainability).
What to do next
If a window or door line is a revenue driver and sells into projects that score whole‑life‑carbon, prioritize an assembly‑level EPD for that family first. Use PremiAL’s verified figures to keep embodied carbon competitive, and publish with an operator recognized in your buyers’ region. The cost of doing nothing is silent. It shows up when a competitor with a ready EPD gets the spec while your team argues equivalence.
References used for numeric context only: UNEP Global Status Report for Buildings and Construction 2024/2025 (UNEP, 2025), LIXIL disclosures on EPD coverage and PremiAL performance (LIXIL, 2025), Reynaers EPD portfolio statement (Reynaers, 2025).
- UNEP Global Status Report 2024/2025 (UNEP, 2025)
- LIXIL environmental reporting and PremiAL press materials (LIXIL, 2025) (Climate and Environment) (PremiAL press)
- Reynaers certified and traceable information page citing current EPD coverage (Reynaers, 2025)
Frequently Asked Questions
Does TOSTEM have product-specific EPDs for windows and doors outside Japan?
As of late 2025, publicly listed EPDs for TOSTEM fenestration outside Japan appear limited. LIXIL reports SuMPO EPDs in Japan for two sash windows and for PremiAL aluminum profiles, plus broader EPD coverage for other brands and categories (LIXIL, 2025).
Which PCR should a window maker choose to publish faster?
Use the current Fenestration Assemblies PCR for full systems where possible, since it aligns with how design teams buy. Your LCA partner should confirm fit and operator preferences for your target market.
Can verified recycled aluminum data shorten EPD timelines?
Yes. If billet and extrusion data are already third‑party verified, upstream A1 to A3 are cleaner. LIXIL’s PremiAL provides such verified data points for aluminum profiles (LIXIL, 2025).
Who are TOSTEM’s likely EPD‑ready competitors?
YKK AP, Kawneer, Schüco, and Reynaers regularly publish EPDs for curtain walls, framing, and windows. Reynaers cites 19 generic EPDs covering 67 product variants (Reynaers, 2025).
About the Author
Walker Ryan is a climate-tech entrepreneur focused on driving industrial decarbonization through better data. As the founder and CEO of Parq, he helps manufacturers generate high-quality, third-party–verified carbon disclosures at scale—accelerating a traditionally slow and expensive process. Before starting Parq, Walker led over $200 million in sustainability-focused investments as VP of Strategy & Growth at ReStream Solutions, following earlier experience in investment banking at Deutsche Bank. He brings a rare mix of capital markets expertise and hands-on sustainability knowledge to tackling the infrastructure of industrial emissions.
