Lancaster · Lancashire
Secondary Glazing in Lancaster
Single-glazed sash windows in Lancaster can stay as they are, with vertical sliding secondary glazing fitted inside to reduce draughts and cold.
- LA1
- LA3
- LA4
- Guide from £465
About secondary glazing listed buildings in Lancaster
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.
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.
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.
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.
What's included
- Written quote fixing the price for the specification
- Advice on opening style, glass and fire escape
- Fitting, sealing and checking every opening panel
- Made-to-measure slim aluminium frames and glass

Lancaster at a glance
- Postcodes covered
- LA1, LA3, LA4 and the surrounding area, including Morecambe, Fleetwood and Thornton-Cleveleys
- Coast
- Lancaster is about 5 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. 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.
- Daylight and sun
- In Lancaster the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.1 hours of daylight, rising to about 59° and 16.9 hours in midsummer. Secondary glazing adds an extra layer of glass, which slightly reduces daylight. Low-iron or clear low-E glass keeps light loss to a minimum, while on sunny elevations solar control glass can help reduce overheating in rooms with large windows.
- Access and setting
- 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.
- Rules in England
- 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.
Guide prices in Lancaster
| 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 |
Get a guide price for your size
Approved Document B covers escape windows. Where an existing window is an escape route, typically in first-floor bedrooms, its replacement should give at least the same escape opening as before.
Options to choose between
Horizontal sliding
Panels slide sideways, suiting wide casement windows and openings where you need regular access for cleaning or ventilation.
Fixed panel
A non-opening unit for windows never opened, giving the most airtight seal for noise and draught reduction.
Hinged casement
Panels open inwards like a door, giving full access to the original window, and can be chosen for escape windows.
Secondary Glazing in Lancaster: questions
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.
Will secondary glazing cause condensation?
It can, if the original window is sealed tighter than the secondary unit, because warm, moist room air then gets trapped in the cavity. The secondary unit should be the more airtight of the two, and the original window should not be fully sealed. Opening the secondary panel lets room air into the cavity, so close it again afterwards.
Do I need permission for secondary glazing on a listed building?
You should seek listed building consent from the council's planning department before installing secondary glazing on a listed building. Secondary glazing is often seen as a reversible, low-impact change, but consent requirements depend on the building. Carrying out works that need consent without it is a criminal offence. If your home is not listed but is in a conservation area, check with the council if you are unsure.
Does secondary glazing need safety glass?
It does in critical locations. In England, glass within 800mm of the floor, glass in doors and glass near doors are critical locations under Approved Document K, and these apply to secondary glazing too. Low-level secondary panes should be toughened or laminated safety glass. The surveyor checks each window during the survey.
Do you cover Lancaster for secondary glazing?
Yes. We can quote for secondary glazing across Lancaster and the surrounding Lancashire area, including postcode districts LA1, LA3 and LA4, and nearby Morecambe, Fleetwood and Thornton-Cleveleys. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Lancaster
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.