1714–1830
Secondary Glazing for Georgian Townhouse
Georgian small-pane sashes are among the hardest windows to upgrade — the glazing bars are decorative, the glass is often original, and the pane count makes replacement impossible. This page explains what we spec, why, and how the job runs from survey to install.
Why georgian townhouse owners choose secondary glazing
A room-side secondary pane preserves every glazing bar and every original hand-drawn pane while blocking draughts and doubling the thermal performance.
Vision HD slim-line profiles finish in satin white or bronze to blend with the reveal — invisible from the street once installed.
Listed-building consent is usually straightforward because the historic fabric is entirely untouched.
Recommended: Heritage & Listed
the conservation officer's preferred upgrade
fully reversible install — no alteration to historic fabric
Historic England and most local conservation officers recommend room-side secondary glazing over replacement double glazing on protected properties — it's the only upgrade that's fully reversible.
Recent installs nearby
St John's Georgian townhouse
Small-pane Georgian sashes protected with Vision HD slim satin white units — invisible from the street.
Nether Edge Grade II sash retrofit
Six original box sashes fitted with balanced vertical secondary sliders — full listed-building consent secured in six weeks.
Ecclesall Road bay-window sound retrofit
Three-panel horizontal sliders across a 3.2 m Edwardian bay — Rw measured at 47 dB post-install.
Local reference points
- Era
- 1714–1830
- Typical window
- small-pane sliding sashes with fine glazing bars
- Top problem
- irreplaceable original glass with heavy heat loss
- Recommended service
- Heritage & Listed
- Recommended product
- vision range
- Performance
- fully reversible install — no alteration to historic fabric
Listed-building consent help — free with every quote
We draft the drawings and specifications your conservation officer needs.
Common questions
Will the install harm the original sashes?
No — the secondary system fits into the reveal, not into the sash box. The original window operates exactly as before.
Do you match the frame colour to my existing joinery?
Yes — powder-coated aluminium is available in white, black, grey, satin anodised or any of 200+ RAL colours, colour-matched on request.
Is listed-building consent needed?
In many cases no, because no historic fabric is altered. Where it is needed we supply drawings and specifications with your quote at no cost.
How does this compare to replacement double glazing?
A modern secondary unit with Low-E glass and a 100 mm cavity outperforms most existing sealed double-glazed units — and it works on windows you legally can't replace.
What if I've got Article 4 restrictions?
Article 4 applies to changes visible from the highway — a room-side install isn't visible from outside so it's usually unaffected.
Next step for georgian townhouse owners
Send us photos of one or two windows and we'll come back with a written quote and a spec sheet you can compare against replacement double glazing.