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 Colne?
In Colne, 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. Prices across the North West are typically 6% below the UK average for this kind of work, which is reflected in the range for Colne. 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 |
What moves the price most:
- Glazing size, specification and lead time
- Overheating and energy design
- Access for large glass panels
- Cladding material
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a glazed extension in Colne?
Whether you need planning permission depends on your house and its location in 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
From survey to sign-off, the job normally involves:
- Structural design for steel frames and glass supports
- Building control sign-off
- Cladding or render finish
- Large-format sliding doors and fixed glazing
- Electrics, heating and finishes
- Contemporary design and planning drawings
How long does it take?
The build itself usually takes 12 to 16 weeks on site; glazing lead times can be 6 to 10 weeks. Allow time beforehand for drawings and approvals, usually 3 to 4 months.
Building in Colne
Terraced streets across the North West often suit rear dormers and single-storey kitchen extensions.
We work across Colne and neighbouring areas such as Nelson, Burnley and Accrington. Postcodes we cover in Colne include BB8.
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
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 Colne
Do you build glazed extensions in Colne?
Yes. We build glazed extensions across Colne, including postcodes BB8. Every project starts with a free home visit.
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.
Does it need planning permission?
The same rules as other extensions apply, but contemporary designs in conservation areas are assessed carefully. We discuss the design approach with you before applying.
How much does a glazed extension cost in Colne?
In Colne, 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.
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.
