A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
From a first conversation about a double-storey extension to the day the site is cleared, homeowners in Kingswood deal with us directly. We come out to measure up at no cost, explain the choices in plain terms and send a written quote. For context, comparable work in the South West usually falls within £61,000–£122,000 including VAT, and it is available across BS15 and BS16.
- Guide price
- £61,000–£122,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- BS15 and BS16
- Planning rules
- England
- Local area
- South Gloucestershire
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Kingswood?
Every figure below is a guide for a double-storey extension in Kingswood, inclusive of VAT. Regional pricing for the South West works out about 2% above the national guide, and the overall span is £61,000–£122,000. The survey costs you nothing, and after it we commit to a firm price for your specification in writing.
| Type of job | What it usually involves | Guide in Kingswood |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £41,000–£66,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £61,000–£122,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £102,000–£184,000 |
Expect these to shape the final quote:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
Scope of the work
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
- Building control inspections and completion certificate
Local housing and a double-storey extension
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.
None of this holds for every street in Kingswood, which is why we look at your actual house before pricing a double-storey extension rather than assuming from its age alone.
Permissions for a double-storey extension in Kingswood
Because Kingswood falls under England's rules, the guidance below is the version relevant to you. Before sending a price, we check your property's position with the council.
In England, a two-storey rear extension can only be permitted development if it is no more than 3 m deep, at least 7 m from the rear boundary and finished to match the house. Most double-storey and all two-storey side extensions need full planning permission.
Building Regulations approval is needed, with structural calculations for beams, foundations and the roof. The Party Wall etc. Act 1996 often applies on semi-detached and terraced houses.
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?
A visit to your home
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 double-storey extension so the price reflects your home.
Price and scope agreed
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a double-storey extension.
Booking the work
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
Build and hand over
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.
Working with SK Home Improvements
Frequently asked questions
How is the new roof joined to the existing house?
The new roof is usually tied into the existing roof so the two read as one. On a rear extension this often means a lower ridge or a hipped end, with valleys where the slopes meet. We strip back some existing tiles, fix new rafters and battens, and lay matching tiles or slates. Lead or proprietary flashings seal the junctions so water runs off properly.
Do I need planning permission in Kingswood?
It depends on the work, the size of the project, your property type and whether the building is listed or in a conservation area. Kingswood 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 long will a double-storey extension take?
On a typical home, allow 14–22 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
Also covering areas around Kingswood
Homes across BS15 and BS16 in Kingswood are within our coverage, as are those in Mangotsfield, Keynsham and Bishopsworth. If you are just outside these areas, ask anyway, because we work right across the UK.

