Glass box extensions in Cumbria
We design and build glass extensions for houses in Cumbria, with a written price once the survey and design are done and one point of contact throughout.
- Guide priceFrom £28,500 inc VAT
- PlanningSame limits as single-storey rear; glazing checked for building regs
- Towns covered7
- Site visitFree, no obligation
Glass extension prices in Cumbria
Labour and material costs vary across the UK, so for Cumbria we use our North West England factor (×0.95). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Cumbria: £2,850 to £5,510 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2 m × 4 m 8 m² | £28,500 – £34,500 | £28,500 – £36,000 | £32,500 – £44,500 |
| 3 m × 4 m 12 m² | £34,000 – £41,500 | £39,500 – £50,500 | £49,000 – £66,500 |
| 3 m × 6 m 18 m² | £51,000 – £62,000 | £59,500 – £75,500 | £73,500 – £99,500 |
For a figure based on your own dimensions, use our guide-price tool.
What is included
- Planning drawings that show the glass detail
- Design with specialist glazing input
- Steel or glass beams and slim-frame glazing
- Whole-house energy calculations where needed
Solar gain is the risk. We specify solar-control glass, plan for opening vents or sliding panels, and avoid fully glazed roofs on south-facing extensions unless shading is included.
Local to Cumbria
Towns we cover in Cumbria include Carlisle, Barrow-in-Furness, Kendal, Whitehaven, Workington, Penrith, Ulverston. The North West has a high share of Victorian and Edwardian terraces with rear yards and outriggers, plus large areas of inter-war semis in the suburbs.
Planning and approvals in Cumbria
In England a glazed or orangery-style extension follows the same size limits as any single-storey rear extension: 3 m or 4 m without an application, or up to 6 m and 8 m through prior approval. Building regulations limit glazing to about a quarter of the new floor area plus the openings it replaces, unless whole-house calculations show the design still performs.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Building over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
Applications are decided by the local planning authority (your district, borough or unitary council).
What happens next
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Cumbria home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a glass extension in Cumbria
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Cumbria, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do I need building regulations approval in Cumbria?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Will my neighbours in Cumbria be involved?
If a planning application or prior approval is needed, the council notifies neighbours. If the work is on or near a shared boundary, party wall notices may also be needed.
How much does a glass extension cost?
Our guide range is about £2,850 to £5,510 per m² including VAT, because structural glass is made to order. A 12 m² standard-spec glass extension is typically £39,500 to £50,500 in Cumbria.
Are glass extensions cold in winter?
Modern double or triple glazing with warm-edge spacers and underfloor heating keeps them comfortable. They are not as warm as a solid room, and we explain the trade-off honestly.
Book a free site visit in Cumbria
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.