Bay Window Secondary GlazingBespoke Units for Every Facet
Bay windows are a period-home centrepiece — and a major source of heat loss and noise. Our made-to-measure secondary glazing follows the exact angles or curve of your bay, sealing every facet for warmth and quiet without altering the window.
Every Bay Shape Covered
No two bays are identical, which is why an off-the-shelf product never fits well. We survey each facet of your bay individually and manufacture units that align precisely with the angles or curve — so the finished installation looks intentional and stays visually discreet.
| Bay type | How we glaze it |
|---|---|
| Square / box bay | Three flat facets at right angles — each glazed with its own aligned panel. |
| Splayed / canted bay | Angled side facets surveyed individually so units meet cleanly at each junction. |
| Bow / curved bay | Multiple narrow panels follow the curve, preserving the sweep of the window. |
| Two-storey bay | Coordinated installation across floors for a consistent finish throughout. |
Why Bays Benefit Most
- Large glazed area. Bays lose more heat than flat windows, so a second insulating layer has the biggest impact on comfort and bills.
- Many joints to seal. Each facet junction is a draught path; sealing them all transforms a cold bay into a usable, cosy space.
- Noise on every angle. Combined with acoustic noise-reduction glazing, a bay can be quietened across its whole span.
- Sash or casement. Many bays contain sashes — see our dedicated sash window secondary glazing page, and our bay window glazing guide.
Invisible From the Street
A bay window is the public face of a Victorian or Edwardian home, so any upgrade has to respect the streetscape. Because our secondary glazing is fitted entirely on the inside of the bay, the original glass, glazing bars and timber remain the only thing visible from outside — nothing changes to the elevation, which is exactly what conservation officers want to see. Internally, slimline frames are powder-coated to match your existing paintwork and set back against the reveal, so they read as part of the window rather than a bolted-on addition. In a curved or splayed bay the units follow the geometry facet by facet, keeping sightlines clean across the whole sweep.
Thermal Comfort for a Cold Corner
Because a bay projects out from the building and carries so much glass, it is almost always the coldest part of the room — which is a shame when it is usually the spot people most want to sit. A single-glazed bay can have a U-value around 5.0 W/m²K, radiating heat straight out on a winter evening. Adding a sealed secondary layer with a generous air gap, and optional Low-E glass, can cut heat loss through the bay by more than 60% and lift its performance close to modern double glazing.
The practical result is a bay you can actually use year-round: no cold downdraught spilling off the glass, far less condensation pooling on the sills, and a warmer, quieter reading nook or window seat. Every unit is bespoke-manufactured to the surveyed angles of your specific bay and installed by heritage-trained fitters, and — like all our systems — it is fully reversible, so it never compromises the original window or your home's value. It all starts with a free, no-obligation survey and a clear written quote.
Browse all secondary glazing types, see costs, or return to our complete guide to secondary glazing. We shape bespoke bay window glazing for period homes across London.
Bay Window Secondary Glazing: FAQs
Common questions about glazing square, splayed, bow and curved bay windows.
What Our Clients Say
Rated 4.9 out of 5 across 127 reviews from London homeowners.
"Exceptional service from start to finish. The noise reduction in our Kensington townhouse is remarkable — we no longer hear the constant traffic on the high street, even in the front bedrooms."
"Specialists who truly understand listed buildings. They handled our Grade II* property with real expertise and managed the conservation paperwork so we didn't have to worry about a thing."
"Our Georgian sash windows were draughty and freezing every winter. The secondary glazing has transformed the house — warmer rooms, lower heating bills, and the original windows look untouched."
"From survey to installation the team was professional and tidy. The fit is so discreet that visitors don't even notice the secondary glazing is there. Sleep has never been better."
"We live near a busy junction and the difference is night and day. The acoustic glass they recommended cut the noise dramatically. Worth every penny for the peace and quiet."
"Honest advice, fair pricing, and beautiful craftsmanship. They talked us through every option without any pressure. I would recommend them to anyone with a period property."
Make Your Bay Warm and Quiet
Book a free survey and we'll measure every facet of your bay and provide a clear, no-obligation quote for a perfectly fitted installation.