Heritage Double Glazing Upgrades in Cheltenham
Slimline heritage double glazing retrofits into your original Regency or Victorian sashes, taking the glass from roughly 5.0 to 1.6 W/m²K without changing external sightlines. Allow two to four weeks including unit manufacture. We deepen rebates by hand and specify everything for Cheltenham Borough Council conservation and listed building consent.
Request a Free Restoration Survey
Tell us about your windows and we will arrange a no-obligation survey, usually within five working days.
Who this suits
This upgrade suits period homes in Montpellier, Lansdown, Pittville, Charlton Kings and Leckhampton where replacement windows would be refused. If a room is cold at the glass, condensates each winter morning, or sits on a busy road, slimline units solve it while keeping the original joinery.
- Period homes in Montpellier, Lansdown and Pittville conservation areas
- Rooms that are cold at the glass despite good heating
- Persistent condensation and mould on winter mornings
- Owners who have been refused permission for uPVC replacements
- Listed buildings where new windows are simply not an option
- Anyone wanting better acoustic performance near busy Cheltenham roads
From survey to installation
Four stages over two to four weeks: assess the frames, support any consent application, prepare and reglaze in the workshop, then refit and seal on site. Rebate deepening and any splices use conservation-grade Accoya or Sapele, bedded with a traditional linseed putty line.
Step 1
Assess the frames
We measure the rebate depth and check the condition of each sash to confirm the window can safely take a unit.
Step 2
Consent support
Where consent is required, we supply unit specifications, sightline sections and glass details for your application.
Step 3
Prepare and reglaze
Sashes are taken to the workshop, rebates deepened, repairs made and units bedded with a traditional putty line.
Step 4
Refit and seal
Sashes are rehung with new cords and heavier weights to match, then draught proofed and finished.
Specification detail
- 11–14mm slimline units with warm-edge spacers and krypton or argon fill
- Low-iron and restoration-textured glass options to mimic original glazing
- Black or bronze spacer bars set back to keep sightlines slender
- Weights uprated so the heavier sash still balances perfectly
- Traditional linseed putty-line finish rather than modern beading on visible faces
- 10-year guarantee on units and installation
We work throughout Montpellier, Pittville, Charlton Kings, Leckhampton, Lansdown and the wider Cheltenham conservation areas. See the full range of sash window repairs in Cheltenham.
Timber vs uPVC Sash Windows for Period Properties
An honest comparison of timber and uPVC sashes: appearance, conservation acceptability, lifespan, repairability and whole-life cost for Cheltenham homes.
Read the guide