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 Muswell Hill?
In Muswell Hill, a glazed extension typically costs £3,650–£5,450 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £65,500–£98,000. The guide for Muswell Hill reflects typical costs in London, roughly 30% above the UK-wide figure. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £47,500–£71,000 |
| Typical project (18 m²) | £65,500–£98,000 |
| Larger project (25 m²) | £91,000–£136,000 |
| Rate per m² | £3,650–£5,450 |
The main things that change the cost:
- Cladding material
- Access for large glass panels
- Overheating and energy design
- Lighting and finishes
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 Muswell Hill?
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
From survey to sign-off, the job normally involves:
- Structural design for steel frames and glass supports
- Electrics, heating and finishes
- Building control sign-off
- Cladding or render finish
- Energy and overheating calculations where needed
- Foundations, walls and insulated roof
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. Design and approvals come first and typically take 3 to 4 months, depending on the approval route.
Building in Muswell Hill
Space is at a premium in London, so homeowners often build out into the side return or up into the roof rather than move.
Our Muswell Hill coverage includes postcode districts N2 and N10, and we also work in nearby places such as Crouch End, Wood Green and Highgate.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and 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 Muswell Hill
Do you build glazed extensions in Muswell Hill?
Yes. We build glazed extensions across Muswell Hill, including postcodes N2 and N10. Every project starts with a free home visit.
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.
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 Muswell Hill?
In Muswell Hill, a glazed extension typically costs £3,650–£5,450 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £65,500–£98,000. Your fixed price depends on the survey and drawings.
Can large glass panels be lifted in?
Some need a crane or glass-lifting robot. We plan access during design.