Extensions and living spaces
Extensions
- Free design survey
- In-house building team
- Written quote before anything is ordered
How it's priced
Priced after a free design survey
Every extensions project is designed for its site, so we don't publish a misleading ‘typical’ price.
- 1We visit, measure and talk through what you want
- 2We design it and check planning and Building Regulations
- 3You get a written quote before anything is ordered
Overview
Why extensions?
We design and build glazed extensions — kitchen extensions with bifolds or sliders, roof lanterns, rooflights and steel-look screens — with our own builders for the structural openings and making good.
Because the glazing and the building work are done by one team, there's one programme, one named project manager and nobody passing problems between trades. Each extension is priced after a free design survey.
One team, one programme
Building and glazing coordinated by one named project manager.
Glazing-led design
Bifolds, sliders, lanterns and rooflights designed in from the start.
In-house builders
Our own team for openings, steels and making good.
Warm and efficient
Insulation, underfloor heating and heat pumps from our other divisions.
Written quote first
Designed and priced before anything is ordered.
Priced after a free design survey
Tell us about your project
- A named project manager from the first visit
- Planning and Building Regulations checked for you
- Our own building team for openings and making good
Styles and options
Made to your specification
Glazing
- Bifold doors
- Sliding and slimline doors
- Roof lanterns
- Flat rooflights
- Steel-look screens
Building
- Structural openings and steels
- Making good and finishing
Comfort
- Floor and roof insulation
- Underfloor heating insulation
- Heat pumps
Good to know
Planning, regulations and timings
Planning permission
Many single-storey rear additions fall under permitted development, within limits on depth, height and position. Those rights don't apply to flats and maisonettes, and they are restricted for listed buildings, conservation areas and homes where they've been removed. We check your property at the design survey.
Building Regulations
Extensions need Building Regulations approval for structure, insulation, drainage, ventilation and fire safety. If you build on or near a shared boundary, the Party Wall Act may apply.
Designed after a free survey
Every one is designed for its site, so there is no honest 'typical' price. We measure and design it at a free design survey, and you get a written quote before anything is ordered.
Questions
Extensions: your questions answered
How much does a glazed extension cost?
Every one is designed for the site, so we price a glazed extension after a free design survey rather than quote a misleading 'typical' figure. You get a written quote before anything is ordered, and nothing is built until you've approved the design.
Do you do the building work as well as the glazing?
Yes. Our in-house building team forms the openings and makes good, and we don't subcontract glazing work.
Do I need planning permission for an extension?
Not always — many single-storey rear extensions are permitted development within limits on depth, height and position. Flats, listed buildings and conservation areas are different; we check at the design survey.
Can I get a price for just the glazing?
Yes. The quote builder prices bifolds, sliders and lanterns by tier — for example, 3 m bifolds start at £4,500–£7,500 in aluminium. Indicative, supplied and installed in London and the South East, including VAT; prices updated 11 October 2026. A survey confirms the final figure.
Keep exploring
Related products and services
Conservatories
Year-round conservatories with insulated roofs and high-performance glass.
Orangeries
Solid-pillared orangeries with roof lanterns — more room than a conservatory, more light than an extension.
Garden rooms
Insulated garden rooms and offices with full-height glazing.
Brands we install
REHAU, SMART, AluK, Schüco, Cortizo, VELUX, FAKRO and Cambridge Skylights — and the tier each sits in.
Begin your project
Talk to us about your project
A free design survey, a written quote before anything is ordered, and one named project manager from start to finish.