Cornwall · England
Secondary Glazing in Cornwall
Our surveyors can measure windows across Cornwall for secondary glazing, checking reveal depth, opening style and fire escape needs before quoting.
- Guide from £465
- 11 towns covered
- Postcode areas EX, PL, TR
Secondary glazing for sash windows in Cornwall
If an existing window is relied on for escape in a fire, the secondary glazing in front of it must open easily and give enough clear opening. The surveyor checks which windows are escape windows, so the opening style and catches do not block a way out.
Owners of listed buildings should seek listed building consent before installing secondary glazing, as the requirements depend on the building and the council. Secondary glazing is often seen as a minimal, reversible change, but carrying out works that need consent without it is a criminal offence.
Secondary glazing can also add security, because an intruder would have to break through two separate windows. Laminated glass and locking catches on the secondary unit add further resistance, which is useful for ground-floor and basement windows in period properties.
Secondary glazing leaves the original window untouched and fits a second, independent window inside it. The air gap between the two works with the glass to reduce noise and heat loss. In most cases the installation can be taken out later without damaging the historic window or reveal.
What applies in Cornwall
Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Approved Document L sets the minimum energy performance for replacement windows and doors in existing homes in England: a U-value of 1.4 W/m²K, or Window Energy Rating band B for windows; doors can instead meet a Door Set Energy Rating (band B, or band C for doors more than 60% glazed); rooflights need 2.2 W/m²K.
Cornwall has its own coastline, so for homes and businesses near the sea, salt air and wind-driven rain are part of the brief. Coastal properties often have older windows exposed to wind-driven rain and draughts. Secondary glazing adds a sealed inner layer that reduces draughts and cold, while the original window keeps out the weather and its condition is protected from inside.
Rural cottages and period homes often have single-glazed timber windows that cannot easily be replaced. Secondary glazing reduces draughts and heat loss in exposed locations, and the surveyor allows for uneven reveals and older plaster when fixing frames.
Guide prices
| Typical job | Guide price inc VAT |
|---|---|
| Slider, 900 × 1200 mm | £465 – £595 |
| Slider, 1200 × 1600 mm | £665 – £845 |
| Acoustic glass, 1000 × 1400 mm | £675 – £865 |
Choosing your secondary glazing
Lift-out panel
A lightweight panel that lifts out of its frame, for windows rarely opened, giving a slim and economical secondary unit.
Fixed panel
A non-opening unit for windows never opened, giving the most airtight seal for noise and draught reduction.
Vertical sliding
Panels slide up and down, with meeting rails aligned to sash windows so the secondary unit is discreet from inside and outside.
Horizontal sliding
Panels slide sideways, suiting wide casement windows and openings where you need regular access for cleaning or ventilation.
Secondary Glazing in Cornwall: questions
Is secondary glazing suitable for rented homes and flats?
Yes. Secondary glazing is fitted inside, so it often avoids the external changes that leases, freeholders or planning rules restrict. It can be removed later with limited making good. Leaseholders should still check their lease for any rules on internal alterations, and landlords should check escape routes are not affected.
How do I clean and look after secondary glazing?
Open or remove the panels as designed, then clean the glass with mild soapy water and a soft cloth. Wipe the aluminium frames and runners, and keep tracks free of dust so panels slide smoothly. Check seals and catches occasionally. Avoid abrasive cleaners, which can scratch coated glass.
Is secondary glazing as good as double glazing?
It depends on the goal. For noise, secondary glazing is often more effective, because the wider gap between the two windows reduces sound better than the narrow cavity of a sealed unit. For heat, a well-sealed secondary unit with low-E glass significantly improves a single-glazed window. It also keeps original windows, which matters in listed buildings.
How much does secondary glazing cost?
The cost depends on the size and number of windows, the opening style, the type of glass, any arched or shaped heads, reveal depth and access. Acoustic and low-E glass cost more than standard clear glass, and shaped frames need more work. See the guide prices for typical windows, then get a written quote after the survey.
Which parts of Cornwall do you cover for secondary glazing?
We cover the whole of Cornwall, including Redruth, Falmouth, St Austell, Truro and Camborne, and postcode areas EX, PL, TR. Building rules for secondary glazing here follow the regulations for England. Enter your postcode on the quote form and we will confirm cover; then a glazier will arrange a free survey before giving you a written quote.
Other glazing services in Cornwall
- Replacement Glass in Cornwall
- Misted Glass Repair in Cornwall
- Emergency Glazing in Cornwall
- Safety Glass in Cornwall
- Window Repairs in Cornwall
- Window Film in Cornwall
- uPVC Windows in Cornwall
- Aluminium Windows in Cornwall
- Sash Windows in Cornwall
- Composite Doors in Cornwall
- Bifold Doors in Cornwall
- Sliding Doors in Cornwall
- Roof Lanterns in Cornwall
- Glass Balustrades in Cornwall
- Frameless Glass in Cornwall
- Shower Screens in Cornwall
- Glass Splashbacks in Cornwall
- Bespoke Mirrors in Cornwall
- Glass Roofs in Cornwall
- Shopfront Glazing in Cornwall
- Curtain Walling in Cornwall
- Glass Partitions in Cornwall
- Property Glazing in Cornwall
Get a written quote in Cornwall
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.