Brecon · Powys
Secondary Glazing in Brecon
Where planning or lease rules limit changes to the outside, secondary glazing in Brecon offers an internal option that can be removed later.
- LD3
- Guide from £465
Secondary glazing listed buildings for homes and businesses in Brecon
A low-emissivity coating on the secondary glass reflects heat back into the room and improves the insulation of the combined window. It is a useful choice for single-glazed sash and casement windows where the originals must be kept for character or planning reasons.
Slim aluminium frames are designed to sit within the window reveal and line up with the original glazing bars or meeting rails. Matching sightlines keeps the secondary unit discreet from outside and inside, which matters for period homes and conservation areas.
Condensation in the gap between the two windows is reduced by making the secondary unit the more airtight of the two. The original window should not be fully sealed, so any moisture that gets into the cavity can escape outside rather than being trapped against the glass.
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.
Included as standard
- Survey of each window, reveal depth and sightlines
- Removal of packaging and cleaning of new glass
- Made-to-measure slim aluminium frames and glass
- Fitting, sealing and checking every opening panel

About Brecon for this job
- Postcodes covered
- LD3 and the surrounding area, including Brynmawr, Tredegar and Merthyr Tydfil
- Coast
- Brecon is well inland, around 48 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Brecon the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.5 hours of daylight, rising to about 62° and 16.5 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 Wales
- In Wales, Approved Document N covers safety glazing: safety glass is needed in and around doors and in low-level glazing where people could walk into it.
Guide prices in Brecon
| 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 Wales need listed building consent for most changes to historic windows; Cadw publishes guidance on looking after traditional windows.
Options to choose between
Lift-out panel
A lightweight panel that lifts out of its frame, for windows rarely opened, giving a slim and economical secondary unit.
Hinged casement
Panels open inwards like a door, giving full access to the original window, and can be chosen for escape windows.
Vertical sliding
Panels slide up and down, with meeting rails aligned to sash windows so the secondary unit is discreet from inside and outside.
Secondary Glazing in Brecon: questions
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.
Can I still open my original windows?
Yes, as long as the secondary glazing has an opening panel in front of the part you need to open. Sliding and hinged panels give access to the original window for ventilation and cleaning. Lift-out and fixed panels suit windows you rarely or never open.
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.
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.
Do you cover Brecon for secondary glazing?
Yes. We can quote for secondary glazing across Brecon and the surrounding Powys area, including postcode districts LD3, and nearby Brynmawr, Tredegar and Merthyr Tydfil. 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 Brecon
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.