What is a glazed extension?
A glazed or contemporary extension uses large panes of glass, slim aluminium frames and modern cladding to create a bright room that contrasts with the original house. Frameless corners, structural glass roofs and minimal sliding doors are typical features.
How much does a glazed extension cost in Barry?
In Barry, a glazed extension typically costs £2,600–£3,850 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £47,000–£69,500. Building costs in Wales run about 8% below the UK average, and the figures for Barry are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £34,000–£50,000 |
| Typical project (18 m²) | £47,000–£69,500 |
| Larger project (25 m²) | £65,000–£96,000 |
| Rate per m² | £2,600–£3,850 |
Your quote will depend mainly on:
- Cladding material
- Access for large glass panels
- Overheating and energy design
- Glazing size, specification and lead time
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a glazed extension in Barry?
The approval route for Barry is set by planning law in Wales. In Wales a single-storey rear extension is often permitted development: up to 4 metres beyond the rear wall and up to 4 metres high, with eaves no higher than 3 metres within 2 metres of a boundary and no more than half the land around the original house covered. Wales has no larger home extension prior approval route, so deeper extensions need a planning application, as do extensions to flats, listed buildings and houses whose rights have been removed.
The Party Wall etc. Act 1996 applies in Wales, so notices must be served before work on a shared wall, on the boundary, or excavation close to a neighbour’s foundations.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
The work we manage on a glazed extension:
- Large-format sliding doors and fixed glazing
- Contemporary design and planning drawings
- Electrics, heating and finishes
- Cladding or render finish
- Energy and overheating calculations where needed
- Building control sign-off
How long does it take?
Build time is typically 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Barry
Terraced houses in Welsh towns often have narrow plots, which suits rear and side return extensions and rear dormers.
From CF62 outwards, we take on projects throughout Barry and the surrounding parts of South Glamorgan.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about glazed extensions in Barry
Is VAT charged?
Yes, VAT at the standard 20% rate applies to extensions. Our guide prices include it.
Will a glass extension be too hot in summer?
It can be if poorly designed. Solar-control glass, roof overhangs and opening vents reduce overheating, and building regulations may require calculations to show the design works.
How long does a glazed extension take in Barry?
Typically 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Design and approvals beforehand usually take 3 to 4 months.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.
How much does a glazed extension cost in Barry?
In Barry, a glazed extension typically costs £2,600–£3,850 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £47,000–£69,500. Your fixed price depends on the survey and drawings.
Do I need planning permission for a glazed extension in Barry?
In Wales a single-storey rear extension is often permitted development: up to 4 metres beyond the rear wall and up to 4 metres high, with eaves no higher than 3 metres within 2 metres of a boundary and no more than half the land around the original house covered. Wales has no larger home extension prior approval route, so deeper extensions need a planning application, as do extensions to flats, listed buildings and houses whose rights have been removed.