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 Durham?
In Durham, a glazed extension typically costs £2,500–£3,800 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £45,000–£68,500. The guide for Durham reflects typical costs in the North East, roughly 10% below the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £32,500–£49,500 |
| Typical project (18 m²) | £45,000–£68,500 |
| Larger project (25 m²) | £62,500–£95,000 |
| Rate per m² | £2,500–£3,800 |
The biggest cost drivers are:
- Cladding material
- Access for large glass panels
- Lighting and finishes
- Steel framing
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 Durham?
The approval route for Durham is set by planning law 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.
Our first visit includes a check of your planning history, so you know the route before paying for drawings.
What we handle
On a typical glazed extension we handle:
- Large-format sliding doors and fixed glazing
- Contemporary design and planning drawings
- Energy and overheating calculations where needed
- Electrics, heating and finishes
- Structural design for steel frames and glass supports
- Building control sign-off
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. Before that, surveys, drawings and approvals usually take 3 to 4 months, longer if the council asks for changes.
Building in Durham
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Our Durham coverage includes postcode districts DH1, and we also work in nearby places such as Chester-le-Street, Houghton-Le-Spring and Stanley.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 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 Durham
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.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.
How long does a glazed extension take in Durham?
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.
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.
How much does a glazed extension cost in Durham?
In Durham, a glazed extension typically costs £2,500–£3,800 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £45,000–£68,500. Your fixed price depends on the survey and drawings.