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 Sunderland?
In Sunderland, 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. That range is adjusted for the North East, where domestic building work typically costs around 10% below the national average. 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:
- Lighting and finishes
- Cladding material
- Overheating and energy design
- Glazing size, specification and lead time
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 Sunderland?
Approvals for a glazed extension in Sunderland follow the rules for 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.
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:
- Contemporary design and planning drawings
- Foundations, walls and insulated roof
- Structural design for steel frames and glass supports
- Energy and overheating calculations where needed
- Electrics, heating and finishes
- 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 Sunderland
The North East has many terraced streets and post-war semis, where rear extensions and loft conversions are popular ways to gain space.
If your home is in Sunderland or close by in Seaham, Washington and Houghton-Le-Spring, a free home visit is the first step.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 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 Sunderland
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.
Is VAT charged?
Yes, VAT at the standard 20% rate applies to extensions. Our guide prices include it.
Who approves a glazed extension in Sunderland?
Planning matters in Sunderland go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a glazed extension cost in Sunderland?
In Sunderland, 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.
Is triple glazing necessary?
Not always. High-performance double glazing can meet the standards; triple glazing helps in exposed locations.