Two tempered glass panes sealed under vacuum produce a glazing unit just 8.3mm thick, the same visible thickness as the original Georgian or Victorian glass. Combined with slim sashes and putty-glazed external detail, it is the right answer where conventional double glazing would be refused.
Tested air, water and wind performance with whole-window thermal data for your architect or planning consultant.
| Product guidance – as standard | |
| Sill projection | Hardwood. Projections 35 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm |
| Wood moisture content | 12% +/- 2% on delivery |
| Glazing beads | Internally beaded with external rebate up-stand giving the appearance of putty glazing |
| Air permeability | 600 Pa (Class 3) – EN 12207:2017 |
| Water tightness | 200 Pa (Class 5A) – EN 12208:2002 |
| Wind resistance | 1600 Pa (Class 4C) – EN 12210:2016 |
| Whole window U-value | 1.2–1.1 W/m²K to EN ISO 10077-1:2006 |
| Whole window acoustic rating | Rw 29–34 dB tested to BS EN ISO 10140-2:2010 |
| Anticipated life expectancy | 60 years with regular maintenance |
| Product Specification | |
| Material | Engineered laminated pine, hardwood or Accoya. FSC or PEFC certified |
| Finish | Factory finished externally and internally with Teknos water-based microporous opaque to specified RAL or stain (Aqua prime 1410, Aqua mid 2901, Aqua top 2600) |
| Glazing | 8.3–12.3 mm sealed vacuum-glazing unit. Two flat tempered glass panes separated by micro support pillars and sealed with a vacuum chamber |
| Glazing bars | Applied bars to both faces of sealed unit, fixed with double-sided glazing tape and capped with clear silicone |
| Trickle ventilation | Controllable trickle ventilator dependent on frame width. EA 2000, 4400 mm² |
| Child restrictor | Optional 100 mm opening restrictor |
| Operation | Cord, weight and pulley system concealed within the frame. Spring balance option available |
| Timber species | Engineered laminated pine, hardwood or Accoya. FSC or PEFC certified |
| Moisture content | 12% +/- 2% on delivery |
| Ironmongery | Lockable Fitch fastener and two finger pulls to bottom sash. Options in antique brass, polished chrome, satin nickel, polished brass, matt bronze, polished nickel |
| Cill | Hardwood. Projections 35–110 mm |
| Horns | Solid feature horns to top sashes included as standard |
| Sustainability | Fully recyclable glazing units with no noble gases |
| Fixing | Installation per Zyle Fenster recommendations and best building practice |
| Warranty | 10-year manufacturing and material defects; 10-year opaque finishes; 6-year stain finishes; 10-year sealed unit seals; 2-year ironmongery |
Download the Vacuum Glazed Sash brochure, datasheets and CAD details for listed and conservation submissions.
Vacuum glazing brings modern insulation behind a sightline that satisfies the strictest conservation officer. The 8.3mm unit reads as single glazing on the elevation while performing closer to a triple-glazed window.
It is the right specification when planning consent rules out standard double glazing, but you still want a warm, quiet home.
Operated on traditional cords, weights and pulleys, the window is built to last in engineered redwood, hardwood or Accoya, with a solid hardwood cill as standard.
A factory-applied three-coat Teknos finish is hand-applied in any RAL or wood stain, so the window arrives ready to be installed.
Honest answers to the questions period homeowners ask about vacuum glazing, listed building consent and warmth.
Two thin tempered glass panes are separated by tiny support pillars with a vacuum drawn from the cavity. The vacuum dramatically reduces heat loss while keeping the unit visibly slim.
In most cases, yes. The 8.3mm thickness and single-pane appearance mean vacuum glazing is frequently accepted by conservation officers where standard double glazing would be refused.
Whole window U-values of 1.2 to 1.1 W/m²K are typical, a significant improvement on original single-glazed sashes and comparable to a modern double-glazed window.
Vacuum glazing seals are guaranteed for 10 years from delivery. The units contain no noble gases and are fully recyclable at the end of their life.
Yes. Different glass make-ups, including laminated acoustic panes, are available to reach 34 dB or higher, helpful in town and city locations or near busy roads.
A complete service
from design to installation.
We purchased a combination of Alu-Clad windows, Lift & Slide doors and entrance glazing from Zyle Fenster for our family home.
Every member of the team was knowledgeable, approachable and highly professional. Manufacturing quality is outstanding and the installation was carried out with real attention to detail. Even after completion, they followed up to ensure everything was perfect.
It’s rare to find a company that delivers exactly what they promise. We would happily recommend Zyle Fenster to anyone building or renovating a home.
Seán & Emma R. – County Meath
Our architect specified Reynaers aluminium systems and recommended Zyle Fenster for the supply and installation.
The large glazing panels have completely changed the feel of the house while maintaining excellent thermal comfort throughout the winter. The installers were meticulous and every junction was finished beautifully.
It’s refreshing to work with a company that genuinely cares about delivering a quality result.
Niamh F. – County Clare
We chose Schüco aluminium windows and doors through Zyle Fenster for our contemporary home.
Everything about the experience was professional. From technical advice through to installation, the team demonstrated real expertise. The slim profiles look fantastic and the quality of the finish is exactly what we hoped for.
A premium product installed by a premium company.
David L. – County Waterford
Our conservation project required slim glazing without compromising performance, and Zyle Fenster recommended their vacuum glazed timber sash windows.
The result is outstanding. The traditional appearance has been preserved while the improvement in warmth and noise reduction is remarkable. You simply wouldn’t know they contain such advanced technology.
Excellent communication, excellent installation and an exceptional product.
Michael & Sarah K. – County Kilkenny
Finding authentic timber sash windows that also met modern energy standards wasn’t easy until we found Zyle Fenster.
The finished windows perfectly suit our Victorian home while dramatically improving comfort. They operate beautifully and the attention to detail is outstanding.
The installation team treated our home with great respect and left everything spotless each evening. We have received countless compliments from neighbours.
Margaret C. – Dublin
We wanted a large glazed feature overlooking the garden while still achieving excellent thermal performance. The timber curtain wall supplied by Zyle Fenster exceeded every expectation.
The craftsmanship is remarkable and the amount of natural light it brings into the house is incredible. Our architect was particularly impressed with the technical knowledge and attention to detail shown throughout the design process.
Professional, reliable and extremely high-quality workmanship.
Patrick D. – County Wicklow
Whether you are an architect specifying for a new project, a self-builder planning your custom home, or a developer working to a programme, our team is here to help. Get in touch for technical advice, product information, or to request a quote.
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