Barry · South Glamorgan
Secondary Glazing in Barry
Single-glazed sash windows in Barry can stay as they are, with vertical sliding secondary glazing fitted inside to reduce draughts and cold.
- CF62
- CF63
- Guide from £465
Secondary glazing listed buildings in Barry
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.
For noise reduction, the size of the air gap between the original window and the secondary unit matters a great deal, and a wider cavity generally performs better. Acoustic laminated glass and well-sealed frames improve results further, especially against traffic, rail and aircraft noise.
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.
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.
What you get
- Written quote fixing the price for the specification
- Survey of each window, reveal depth and sightlines
- Fitting, sealing and checking every opening panel
- Made-to-measure slim aluminium frames and glass

Local details for Barry
- Postcodes covered
- CF62, CF63 and the surrounding area, including Penarth, Cardiff and Llantwit Major
- Coast
- Barry is about 1 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 Barry 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 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 Barry
| 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
Wales sets its own energy standards in the Welsh Approved Document L. Replacement windows, doors and rooflights must meet the limiting values set there, which your quote will reference.
What you can choose
Low-E glass
Coated glass that reflects heat back into the room, improving insulation when the original window is single glazed.
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 Barry: questions
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.
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.
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.
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.
Do you cover Barry for secondary glazing?
Yes. We can quote for secondary glazing across Barry and the surrounding South Glamorgan area, including postcode districts CF62 and CF63, and nearby Penarth, Cardiff and Llantwit Major. 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 Barry
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.