A single-storey extension is a new ground-floor room built onto your house, usually at the rear or side, with its own foundations, walls and roof, creating a bigger kitchen, living space or bedroom without moving home.
Anyone planning a single-storey extension in Cheltenham wants three things: a clear price, a realistic timetable and a tidy job. We publish a guide of £35,500–£76,000 including VAT for the South West up front, explain that work normally takes 10–16 weeks on site, and confirm both in writing after a free survey of your property.
- Guide price
- £35,500–£76,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- GL50, GL51 and GL53
- Planning rules
- England
- Local area
- Gloucestershire
- Survey
- Free, with a written quote
Single-storey extensions prices in Cheltenham
No two jobs cost exactly the same, but the ranges below give a fair picture of a single-storey extension in Cheltenham. Pricing for the South West runs about 2% above the national guide, and the overall guide is £35,500–£76,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Cheltenham |
|---|---|---|
| Small extension (8–12m²) | A modest rear or side extension, such as a utility room or a slightly larger kitchen. | £22,500–£41,000 |
| Typical rear extension (15–25m²) | A kitchen-diner or family room with bifold doors and a rooflight or lantern. | £35,500–£76,000 |
| Large or wrap-around (30m² plus) | A wrap-around or wide rear extension, often with structural steelwork into the house. | £71,000–£133,000 |
What moves the price up or down:
- Floor area, shape and number of corners
- Roof type, rooflights, lanterns and the amount of glazing
- Ground conditions, foundation depth and drains to divert
- Finishes, kitchen, flooring and heating specification
What’s included?
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Steel beams to open into the existing house
- Electrics and plumbing by qualified trades, with certificates
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
What are homes like around Cheltenham?
Golden Cotswold limestone defines towns and villages such as Cirencester, Stow and Tetbury, often with stone-slate roofs. Cheltenham is known for Regency stucco terraces and villas, Gloucester has Victorian brick terraces and interwar estates, the Stroud valleys have mill-era stone cottages, and the Forest of Dean uses its own sandstone.
Cotswold stone homes often need lime pointing, stone repairs and windows that suit conservation areas. Regency houses may call for render and decorating, while brick terraces and estate homes suit loft rooms and extensions.
That mix of housing shapes how we approach a single-storey extension in Cheltenham: the age and construction of your home affect the materials, the method and, in the end, the price.
Do you need permission in Cheltenham?
Cheltenham is in England, so the planning and building rules set out below are the ones that apply. We confirm the details with the council before we quote.
In England, many single-storey rear extensions are permitted development: typically up to 3 m deep on a semi-detached or terraced house and 4 m on a detached house, no more than 4 m high, and covering no more than half the land around the original house. Larger rear extensions can go through the prior approval process. Side extensions, flats, listed buildings, conservation areas and homes where permitted development rights have been removed need planning permission.
Building Regulations approval is needed for almost every extension, covering foundations, structure, insulation, drainage, ventilation and fire safety. If the work is on or near a shared wall or boundary, the Party Wall etc. Act 1996 may apply.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Free site survey
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a single-storey extension so the price reflects your home.
Quote in writing
After the survey we send a quote for a single-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Dates and permissions
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a single-storey extension are in place before the first day on site.
Finish and handover
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
How we work
Single-storey extensions in Cheltenham: questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a single-storey extension, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
Do I need planning permission in Cheltenham?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Cheltenham is in England, so England's rules apply. Many smaller jobs need no planning application, but some still need building control approval. We check what applies to your address before quoting.
How much does a single-storey extension cost?
A typical single-storey rear extension of 15–25m² costs £35,500–£76,000, built to a plastered finish ready for your kitchen and decoration. As a guide, allow roughly £1,600–£2,800 per square metre plus fixed costs for groundworks, steelwork and fees. Smaller extensions cost more per square metre. The kitchen, flooring and large glazed doors are usually the biggest extras. We confirm a fixed price for the agreed specification after the survey.
Do I need an architect for an extension?
You need proper drawings for an extension, but not always a full architect service. A designer or architectural technician can produce planning and building regulations drawings, and a structural engineer provides beam and foundation calculations. If you already have drawings, we price from them. If not, we can arrange the drawings and calculations as part of the project so everything is coordinated from the start.
Do I need planning permission for a single-storey extension?
Whether you need planning permission depends on the extension's size and height, how close it is to boundaries, your home's location, whether it is listed or in a conservation area, and which UK nation you live in. In England, many rear extensions up to 3m deep on a semi or terrace, or 4m on a detached house, can be built under permitted development. We check the rules that apply to your home before quoting.
Nearby towns
We cover every part of Cheltenham, including GL50, GL51 and GL53, and nearby Tewkesbury, Gloucester and Stroud. Wherever you are within that patch, the survey is free and the quote comes to you in writing.

