Antrim · County Antrim
Secondary Glazing in Antrim
Secondary glazing in Antrim keeps your original windows in place while adding a slim inner window to cut noise, draughts and heat loss.
- BT41
- Guide from £465
Internal secondary windows across Antrim
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.
The price of secondary glazing depends on the size and number of windows, the opening style, the glass specification, any shaped or arched heads, reveal depth and condition, and access. Acoustic laminated glass and shaped frames cost more than standard clear glass in rectangular frames.
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.
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.
What's included
- Advice on opening style, glass and fire escape
- Survey of each window, reveal depth and sightlines
- Removal of packaging and cleaning of new glass
- Written quote fixing the price for the specification

Local details for Antrim
- Postcodes covered
- BT41 and the surrounding area, including Ballyclare, Ballymena and Newtownabbey
- Coast
- Antrim is well inland, around 20 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Antrim the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.0 hours of daylight, rising to about 59° and 17.0 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 Northern Ireland
- Technical Booklet V covers safety glazing in Northern Ireland, including glass in and around doors and low-level glazing where people could walk into it.
Guide prices in Antrim
| 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
Where a window provides an escape route, its replacement in Northern Ireland should give at least the same escape opening as before.
Choosing your secondary glazing
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.
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 Antrim: questions
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 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.
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.
Do you cover Antrim for secondary glazing?
Yes. We can quote for secondary glazing across Antrim and the surrounding County Antrim area, including postcode districts BT41, and nearby Ballyclare, Ballymena and Newtownabbey. 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 Antrim
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.