Windows · other glazing
Secondary glazing
Secondary glazing is a second, slim window fitted inside the existing one. It keeps the original window as it is, which is why it is the usual answer for listed buildings and conservation areas, and it is one of the most effective ways to cut traffic noise.
Is it right for your home?
Suits
- Listed buildings and conservation areas
- Rented flats where the windows cannot be changed
- Rooms on noisy roads
Good points
- Keeps original windows untouched
- Very good at reducing noise
- Cheaper than replacing the window
Watch out for
- Two windows to open and clean
- Not as warm as a new double glazed window
- Needs a sill or reveal deep enough to fix to
What secondary glazing costs
Secondary glazing typically costs £280 (one secondary glazed panel inside an existing window), with most jobs between £180 and £400. That includes VAT at 20%. Fitting takes 1–3 hours on site.
What you would actually pay
Typical one secondary glazed panel inside an existing window · UK- Typical installed cost Secondary glazing, supplied and fitted
- £233
- VAT at 20% Standard rate
- £47
- Net cost to you
- £280
If you borrowed £280.00 over 36 months at 0.0%, it would cost £7.78 a month – £280.00 in total, of which £0.00 is interest. The last payment would be £7.70.
Illustration only – not a quote, not an offer of credit, and not financial advice. Rates depend on your circumstances and creditworthiness.
Where the money goes
| Element | Typical range |
|---|---|
| Secondary panel A slim aluminium or uPVC frame with glass, made to the size of the reveal: sliding, hinged or lift-out. | £130 – £310 |
| Fitting Fixing the frame inside the reveal and sealing it. | £50 – £80 |
Guide prices including VAT. Your actual cost depends on your home, access and specification.
What moves the price
- Opening type
Fixed and lift-out panels are cheapest. Vertical sliders, which match sash windows, cost the most.
- Glass
Acoustic laminated glass costs more but makes the biggest difference to noise.
- Gap
For noise, a wider gap between the old and new glass works better, so the reveal depth matters.
What should be in a quote
If a quote is missing any of these, ask why before you compare it with another.
- How each panel opens: sliding, hinged or lift-out
- The glass, including acoustic laminated glass if noise is the aim
- The gap between the old and new glass
- The frame colour and how it is fixed
- Whether it can be removed without damaging the original window
- The guarantee
Prices by region
Labour is most of the difference. Typical price (one secondary glazed panel inside an existing window), including VAT.
| Region | Typical | vs UK average |
|---|---|---|
| London | £350 | +25% |
| South East | £320 | +17% |
| South West | £300 | +10% |
| East of England | £290 | +6% |
| West Midlands | £290 | +4% |
| Scotland | £280 | +2% |
| East Midlands | £280 | UK average |
| Yorkshire and the Humber | £280 | UK average |
| North West | £270 | −2% |
| North East | £260 | −5% |
| Wales | £260 | −6% |
| Northern Ireland | £240 | −12% |
Common questions
Do I need permission for secondary glazing in a listed building?
Usually not if it is reversible and does not harm the original window, but councils differ, so ask the conservation officer before ordering.
Does secondary glazing stop condensation?
It usually reduces it on the original window. Seal the new panel well, because damp air getting between the two will condense on the cold outer glass.
Get quotes for your home
A guide price only takes you so far. Local firms can price the work on your own home, and comparing a few quotes is the quickest way to see what is reasonable.
Compare free quotes