County Durham · England
Secondary Glazing in County Durham
Single-glazed sash windows in County Durham can stay as they are, with vertical sliding secondary glazing fitted inside to reduce draughts and cold.
- Guide from £465
- 12 towns covered
- Postcode areas DH, DL, SR, TS
Secondary glazing in County Durham
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.
Glass for secondary glazing is heavy, so the frames need firm fixings into the reveal or a supporting sub-frame. The surveyor checks that plaster, timber linings and window boards are sound enough to carry the weight, and allows for any packing needed in uneven reveals.
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.
Opening styles include vertical sliders that line up with sash window meeting rails, horizontal sliders for wide openings, hinged casements, lift-out panels for windows that are rarely opened, and fixed panes. The choice depends on how you use the window, cleaning access and fire escape needs.

Towns we cover for secondary glazing in County Durham
Choose your town for local details, nearby areas and the postcode districts we cover.
What applies in County Durham
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.
County Durham 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
Low-E glass
Coated glass that reflects heat back into the room, improving insulation when the original window is single glazed.
Acoustic laminated glass
Laminated glass with a sound-dampening interlayer, combined with a generous cavity, for properties affected by traffic, rail or aircraft noise.
Fixed panel
A non-opening unit for windows never opened, giving the most airtight seal for noise and draught reduction.
Lift-out panel
A lightweight panel that lifts out of its frame, for windows rarely opened, giving a slim and economical secondary unit.
Secondary Glazing in County Durham: questions
How much noise does secondary glazing block?
Results depend on the size of the gap between the windows, the glass type and thickness, the seals and the original window. A larger cavity and acoustic laminated glass give the strongest improvement. The survey checks reveal depth and noise sources, so the specification can be tailored to the noise you are dealing with.
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 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 opening style should I choose?
Choose based on how you use the window. Vertical sliders suit sash windows and keep meeting rails aligned. Horizontal sliders suit wide windows. Hinged panels give full access for cleaning and escape. Lift-out and fixed panels suit windows that are rarely or never opened, and give the tightest seal for noise.
Which parts of County Durham do you cover for secondary glazing?
We cover the whole of County Durham, including Darlington, Hartlepool, Stockton-on-Tees, Durham and Chester-le-Street, and postcode areas DH, DL, SR, TS. 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 County Durham
- Replacement Glass in County Durham
- Misted Glass Repair in County Durham
- Emergency Glazing in County Durham
- Safety Glass in County Durham
- Window Repairs in County Durham
- Window Film in County Durham
- uPVC Windows in County Durham
- Aluminium Windows in County Durham
- Sash Windows in County Durham
- Composite Doors in County Durham
- Bifold Doors in County Durham
- Sliding Doors in County Durham
- Roof Lanterns in County Durham
- Glass Balustrades in County Durham
- Frameless Glass in County Durham
- Shower Screens in County Durham
- Glass Splashbacks in County Durham
- Bespoke Mirrors in County Durham
- Glass Roofs in County Durham
- Shopfront Glazing in County Durham
- Curtain Walling in County Durham
- Glass Partitions in County Durham
- Property Glazing in County Durham
All glazing in County Durham · Secondary Glazing across the UK
Get a written quote in County Durham
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.