Greenwich · Greater London
Secondary Glazing in Greenwich
We can quote for secondary glazing in Greenwich with acoustic laminated, low-E or safety glass, in sliding, hinged, lift-out or fixed panels.
- SE3
- SE7
- SE10
- SE12
- Guide from £465
Internal secondary windows for homes and businesses in Greenwich
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.
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.
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.
Included as standard
- Advice on opening style, glass and fire escape
- Survey of each window, reveal depth and sightlines
- Written quote fixing the price for the specification
- Fitting, sealing and checking every opening panel
Working in Greenwich
- Postcodes covered
- SE3, SE7, SE10, SE12 and the surrounding area, including Blackheath, Lewisham and Catford
- Coast
- Greenwich is well inland, around 26 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Greenwich the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 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 Greenwich
| 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
Listed buildings in England need listed building consent for most changes to historic windows or glass, and conservation areas can restrict changes visible from the street. Speak to the council's conservation officer before ordering.
Specification choices
Acoustic laminated glass
Laminated glass with a sound-dampening interlayer, combined with a generous cavity, for properties affected by traffic, rail or aircraft noise.
Hinged casement
Panels open inwards like a door, giving full access to the original window, and can be chosen for escape windows.
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 Greenwich: questions
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.
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.
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.
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 you cover Greenwich for secondary glazing?
Yes. We can quote for secondary glazing across Greenwich and the surrounding Greater London area, including postcode districts SE3, SE7, SE10 and SE12, and nearby Blackheath, Lewisham and Catford. 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 Greenwich
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.