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 Doncaster?
In Doncaster, a glazed extension typically costs £2,600–£3,900 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £47,000–£70,000. Prices across Yorkshire and the Humber are typically 7% below the UK average for this kind of work, which is reflected in the range for Doncaster. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £34,000–£50,500 |
| Typical project (18 m²) | £47,000–£70,000 |
| Larger project (25 m²) | £65,000–£97,500 |
| Rate per m² | £2,600–£3,900 |
Your quote will depend mainly on:
- Steel framing
- Access for large glass panels
- Glazing size, specification and lead time
- Lighting and finishes
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 Doncaster?
The approval route for Doncaster 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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
On a typical glazed extension we handle:
- Building control sign-off
- Large-format sliding doors and fixed glazing
- Cladding or render finish
- Contemporary design and planning drawings
- Structural design for steel frames and glass supports
- Electrics, heating and finishes
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 Doncaster
Yorkshire and the Humber has stone and brick terraces as well as inter-war and newer estates, so materials matching is an early design question.
We work across Doncaster and neighbouring areas such as Bentley, Adwick le Street and South Elmsall. Postcodes we cover in Doncaster include DN1, DN2 and DN55.
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
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 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 Doncaster
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.
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 Doncaster?
In Doncaster, a glazed extension typically costs £2,600–£3,900 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £47,000–£70,000. Your fixed price depends on the survey and drawings.
Do you build glazed extensions in Doncaster?
Yes. We build glazed extensions across Doncaster, including postcodes DN1, DN2 and DN55. Every project starts with a free home visit.
