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.
Every house in Gloucester is a little different, so we never price a single-storey extension from a brochure. We look at the structure, access and existing finishes first, then put in writing a fixed figure for the scope we settle on. As a rough steer, homeowners in the South West should budget £35,500–£76,000 including VAT, with work typically taking 10–16 weeks on site.
- Guide price
- £35,500–£76,000 inc VAT
- Time on site
- 10–16 weeks on site
- Postcodes
- GL1, GL2 and GL4
- Planning rules
- England
- Local area
- Gloucestershire
- Survey
- Free, with a written quote
What should you budget for a single-storey extension in Gloucester?
Here is how the guide price for a single-storey extension breaks down in Gloucester. We start from national figures and adjust for the South West, which comes out about 2% above the national guide. The resulting range, VAT included, is £35,500–£76,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Gloucester |
|---|---|---|
| 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 |
The main things that change the figure:
- Floor area, shape and number of corners
- Ground conditions, foundation depth and drains to divert
- Steelwork needed to open into the existing house
- Finishes, kitchen, flooring and heating specification
Scope of the work
- Groundworks, foundations and below-ground drainage
- Cavity walls built and insulated to building regulations
- Flat or pitched roof, with rooflights or a lantern if specified
- Windows and external doors, including bifolds if chosen
- Plastering, screed floor and internal doors
- Building control inspections and completion certificate
Building in Gloucester
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.
Knowing the typical building types in Gloucestershire helps, but a survey of your own home in Gloucester is what decides the right approach to a single-storey extension.
Permissions for a single-storey extension in Gloucester
Gloucester 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.
From survey to handover
Free site survey
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a single-storey extension, and photograph or measure anything the quote needs to reflect.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Booking the work
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Gloucester property.
On site to finish
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Why homeowners choose us
Common questions
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 you cover Cheltenham, Stroud and Tewkesbury?
Yes. As well as Gloucester, we cover Cheltenham, Stroud and Tewkesbury and the rest of Gloucestershire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
How much will a single-storey extension cost in Gloucester?
As a guide, expect to pay £35,500–£76,000 including VAT for a single-storey extension in Gloucester. That range is adjusted for the South West, which runs about 2% above the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Is a flat roof or a pitched roof better on an extension?
A flat roof is quicker to build and usually costs less, gives a clean modern look and works well with a roof lantern. A pitched roof matches the main house, sheds water faster and allows a vaulted ceiling, but it costs more and its height can affect neighbours. Modern flat roofs in EPDM rubber or GRP last well when properly detailed. Planning rules on height can also decide the choice.
Near Gloucester
Our coverage in Gloucester includes GL1, GL2 and GL4. We also travel to Cheltenham, Stroud and Tewkesbury, so neighbouring addresses are looked after on exactly the same terms as those in town.