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 Darlington?
In Darlington, 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. Prices across the North East are typically 10% below the UK average for this kind of work, which is reflected in the range for Darlington. 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 |
Your quote will depend mainly on:
- Overheating and energy design
- Glazing size, specification and lead time
- Lighting and finishes
- 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 Darlington?
Here is how the rules work for a glazed extension 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.
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:
- Electrics, heating and finishes
- Building control sign-off
- Foundations, walls and insulated roof
- Large-format sliding doors and fixed glazing
- Cladding or render finish
- Structural design for steel frames and glass supports
How long does it take?
Build time is typically 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 Darlington
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
We work across Darlington and neighbouring areas such as Newton Aycliffe, Yarm and Stockton-on-Tees. Postcodes we cover in Darlington include DL3 and DL98.
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 Darlington
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.
Do you build glazed extensions in Darlington?
Yes. We build glazed extensions across Darlington, including postcodes DL3 and DL98. Every project starts with a free home visit.
How much does a glazed extension cost in Darlington?
In Darlington, 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.
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.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.