Fenestration
DGU Series — Double Glazed Windows
A DGU (double glazed unit) window seals two panes of glass around an insulating air or gas gap — roughly 24mm of total build-up — cutting heat transfer and outside noise more than a single pane can. The frame section runs deeper to hold it, and the seal at the spacer is the part that has to be right.
What matters about this product
- Meaningful thermal improvement.
- The sealed gap between panes cuts heat transfer noticeably against a single-glazed window of the same frame type.
- Noticeably quieter.
- Two panes and an air gap attenuate outside noise better than single glazing — worth specifying on a road-facing elevation.
- 24mm typical build-up.
- Two panes plus spacer bring the total glass thickness to around 24mm, so the frame profile has to be sized for it from the start.
- Works in any of our sliding or casement frames.
- DGU is a glass specification, not a separate window system — it fits into a Domal, Bombay or casement frame sized to take it.
- Costs more than single glazing.
- The extra glass, spacer and sealing work add to the price — reserve it for elevations where thermal or acoustic performance genuinely matters, not every opening in the house.
- The seal is what to ask about.
- A failed edge seal shows up years later as fogging or condensation trapped between the panes — ask what sealant and spacer system is being used, since that's what determines how long the unit stays clear.
Specifications
- Total glass build-up
- ~24mm (two panes + spacer)
- Compatible frames
- Domal, Bombay slider, casement
- Performance
- Improved thermal insulation and acoustic dampening
- Typical use
- Road-facing rooms, bedrooms, air-conditioned spaces
Questions people actually ask
Is DGU worth it over standard single glazing?
For a road-facing room, a bedroom, or a space that's air-conditioned most of the year, yes — the thermal and acoustic difference is real. For a back-of-house utility opening, single glazing does the job for less.
What can go wrong with a DGU window?
The one failure mode is the edge seal — if it degrades, moisture gets between the panes and shows as permanent fogging that can't be cleaned from outside. Ask what spacer and sealant system is used; it's the part of the unit that determines its working life.
Does it fit a standard window frame?
It needs a frame profile sized for the thicker glass build-up — around 24mm total — so it's specified into the frame at the design stage rather than retrofitted into an existing single-glazed frame.
Which frame styles is it available in?
Any of our sliding (Domal, Bombay) or casement frames can be built to take a DGU unit; it's a glass specification layered onto the frame choice, not a separate product line.
Related products
Domal Windows
Slimmer-sightline premium aluminium sliding windows for Lucknow — a step up in extrusion precision and sealing from a standard slider.
Casement Windows
Hinged aluminium casement windows for Lucknow — full-aperture ventilation and a tighter seal than a sliding window.
Toughened Glass Works
Toughened safety glass fabrication for Lucknow doors, railings and partitions — heat-strengthened for impact safety.