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 Dronfield?
In Dronfield, a glazed extension typically costs £2,650–£4,000 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £47,500–£72,000. Prices across the East Midlands are typically 5% below the UK average for this kind of work, which is reflected in the range for Dronfield. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £34,500–£52,000 |
| Typical project (18 m²) | £47,500–£72,000 |
| Larger project (25 m²) | £66,000–£100,000 |
| Rate per m² | £2,650–£4,000 |
The biggest cost drivers are:
- Glazing size, specification and lead time
- Overheating and energy design
- Access for large glass panels
- Steel framing
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 Dronfield?
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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
We check this for your address before design work starts, so there are no surprises later.
What we handle
Handled as part of most glazed extensions:
- Foundations, walls and insulated roof
- Energy and overheating calculations where needed
- Large-format sliding doors and fixed glazing
- Cladding or render finish
- Building control sign-off
- 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 Dronfield
The East Midlands has a mix of red-brick terraces, inter-war semis and newer estates, so rear extensions and garage conversions are common projects.
Projects in Dronfield (S18) 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 sign-off
We run the build to a written programme and hand over the completion certificate.
Questions about glazed extensions in Dronfield
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.
Is VAT charged?
Yes, VAT at the standard 20% rate applies to extensions. Our guide prices include it.
How much does a glazed extension cost in Dronfield?
In Dronfield, a glazed extension typically costs £2,650–£4,000 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £47,500–£72,000. Your fixed price depends on the survey and drawings.
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.
How long does a glazed extension take in Dronfield?
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.
