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 Croydon?
In Croydon, 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. Building costs in London run about 30% above the UK average, and the figures for Croydon are adjusted to reflect that. 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 |
Your quote will depend mainly on:
- Overheating and energy design
- Access for large glass panels
- Steel framing
- Cladding material
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 Croydon?
Before anything is built in Croydon, 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.
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
The work we manage on a glazed extension:
- Contemporary design and planning drawings
- Cladding or render finish
- Structural design for steel frames and glass supports
- Foundations, walls and insulated roof
- Large-format sliding doors and fixed glazing
- Electrics, heating and finishes
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 Croydon
Victorian and Edwardian terraces dominate many London streets, which is why side return, wraparound and mansard projects are so common here.
Our Croydon coverage includes postcode districts CR0, CR7, CR9 and CR90, and we also work in nearby places such as Carshalton, Wallington and Mitcham.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 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 Croydon
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.
Do you build glazed extensions in Croydon?
Yes. We build glazed extensions across Croydon, including postcodes CR0, CR7, CR9 and CR90. Every project starts with a free home visit.
How much does a glazed extension cost in Croydon?
In Croydon, 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.
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.