Windows that approach zero.
GlasFëns builds pultruded-fiberglass windows and doors around a hybrid vacuum-glass insulating unit: European-engineered frames, German hardware, and glass that behaves like a wall. Made to order for multifamily, passive house and prefab projects across North America.
Fiberglass for the envelope. Aluminum for the storm.
Fiberglass windows & doors
- GR85 and GR70 pultruded fiberglass profiles
- Hybrid vacuum IGU standard: ZERO glass packages
- Fixed, tilt-turn, outswing casement (with or without integrated screen), dual action
- Passive house and Massachusetts Specialized Energy Code ready
Aluminum hurricane windows & doors
- Thermally broken aluminum for impact and high-wind zones
- Windows, doors, sliding and folding systems
- Florida, Gulf and coastal projects
- Details and renderings coming soon
The glass does the work.
Every GlasFëns glazing unit is a hybrid: an outer lite, an argon-filled cavity, and a LandVac vacuum insulating glass unit on the inside. The vacuum layer is 0.3 mm thick and does what a 100 mm cavity cannot: it removes conduction and convection almost entirely. We never sell bare vacuum glass; the outer lite protects the vacuum unit and carries the coatings.
Packages are named for their center-of-glass performance in US units, in even steps: ZERO 08 is a U-factor of 0.08. Climate-specific coating strategies are grouped as KØLD (cold) and HEIT (hot).
ZERO glass packages →Center-of-glass U-factor × 100
The badge number is the center-of-glass U-factor in US units, in even steps. ZERO 08 = U 0.08.
Cold and mixed climates
Low-E on the cavity side of the outer lite and on the vacuum side, tuned for heating-dominated buildings.
Hot climates
Solar-control coatings for cooling-dominated regions, paired with the A-Series where impact rating is required.
Built for multifamily, passive house and prefab.
Multifamily
Punched-window and window-wall packages for 10–50 unit buildings across the Northeast, engineered to order with procurement timed to the construction schedule.
Passive house
Phius and PHI projects where the window decides whether the envelope closes. Whole-window U-values approaching zero, minimal thermal bridging, exceptional airtightness.
Prefab & modular
Factory-friendly units with consistent profiles and predictable lead times for modular and panelized builders nationwide.
The code is moving toward passive house. So are we.
The Massachusetts Specialized Energy Code requires passive-house-grade envelopes for new multifamily buildings over 12,000 sq ft in a growing list of towns. GlasFëns was built in Massachusetts for exactly these projects, with code approvals for vacuum-glass windows already obtained in New York City and Newton, MA using LBNL WINDOW calculations.
Talk to us about a project
