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 Felixstowe?
In Felixstowe, a glazed extension typically costs £2,950–£4,450 per m² of floor area, including VAT at 20% (standard rate). For a typical 18 m² project that is roughly £53,000–£80,000. We start from a UK-wide guide and adjust it for the East of England, where labour and materials are typically about 6% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| Smaller project (13 m²) | £38,500–£58,000 |
| Typical project (18 m²) | £53,000–£80,000 |
| Larger project (25 m²) | £74,000–£111,000 |
| Rate per m² | £2,950–£4,450 |
The main things that change the cost:
- Overheating and energy design
- Cladding material
- Lighting and finishes
- Steel framing
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a glazed extension in Felixstowe?
Before anything is built in Felixstowe, we confirm which approvals apply 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
The work we manage on a glazed extension:
- Electrics, heating and finishes
- Cladding or render finish
- Energy and overheating calculations where needed
- Large-format sliding doors and fixed glazing
- Structural design for steel frames and glass supports
- Foundations, walls and insulated roof
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 Felixstowe
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
If your home is in Felixstowe or close by in Harwich, Ipswich and Clacton-on-Sea, a free home visit is the first step.
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 handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about glazed extensions in Felixstowe
How long does a glazed extension take in Felixstowe?
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.
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 Felixstowe?
In Felixstowe, a glazed extension typically costs £2,950–£4,450 per m² of floor area, including VAT at 20% (standard rate). A typical 18 m² project comes to roughly £53,000–£80,000. Your fixed price depends on the survey and drawings.
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.
