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 Barrow in Furness?
In Barrow in Furness, a glazed extension typically costs £2,650–£3,950 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £47,500–£71,000. Building costs in the North West run about 6% below the UK average, and the figures for Barrow in Furness are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £34,500–£51,500 |
| Typical project (18 m²) | £47,500–£71,000 |
| Larger project (25 m²) | £66,000–£99,000 |
| Rate per m² | £2,650–£3,950 |
The main things that change the cost:
- Access for large glass panels
- Steel framing
- Overheating and energy design
- Cladding material
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a glazed extension in Barrow in Furness?
Approvals for a glazed extension in Barrow in Furness follow the rules for England. In England a single-storey rear extension is often permitted development: broadly up to 3 metres deep on a semi-detached or terraced house and 4 metres on a detached house, no higher than 4 metres, with eaves no higher than 3 metres within 2 metres of a boundary, and covering no more than half the garden. The larger home extension scheme allows up to 6 or 8 metres if you notify the council first and neighbours have a chance to comment. In conservation areas, National Parks and National Landscapes the larger home extension route, side extensions and cladding are not permitted development. Flats and houses whose rights have been removed need a planning application, and listed buildings need listed building consent.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
On a typical glazed extension we handle:
- Structural design for steel frames and glass supports
- Building control sign-off
- Contemporary design and planning drawings
- Electrics, heating and finishes
- Cladding or render finish
- Foundations, walls and insulated roof
How long does it take?
Expect 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Barrow in Furness
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
Projects in Barrow in Furness (LA14) are surveyed in person before we quote, so the price reflects your actual property.
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
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about glazed extensions in Barrow in Furness
How much does a glazed extension cost in Barrow in Furness?
In Barrow in Furness, a glazed extension typically costs £2,650–£3,950 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £47,500–£71,000. Your fixed price depends on the survey and drawings.
Do you build glazed extensions in Barrow in Furness?
Yes. We build glazed extensions across Barrow in Furness, including postcodes LA14. Every project starts with a free home visit.
How long do large glass panels take to arrive?
Often 6 to 10 weeks after final measurements, so we order them as soon as the structure is built.
Is VAT charged?
Yes, VAT at the standard 20% rate applies to extensions. Our guide prices include it.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.
