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.
Homeowners in Welshpool usually consider a double-storey extension for one of a few reasons: something has worn out, the house no longer suits the way they live, or they are getting it ready to sell. We visit, agree a specification and put a fixed price in writing. Most jobs like this take 14–22 weeks on site, and we work across Powys, including Newtown, Oswestry and Shrewsbury.
- Guide price
- £55,000–£110,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- SY21
- Planning rules
- Wales
- Local area
- Powys
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Welshpool?
Below is a breakdown of typical costs for a double-storey extension in Welshpool. Because rates in Wales are about 8% below the national guide, the overall guide comes to £55,000–£110,000, including VAT. Size, materials and access move the figure, and a free-of-charge survey settles it.
| Type of job | What it usually involves | Guide in Welshpool |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £37,000–£60,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £55,000–£110,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £92,000–£166,000 |
Your price depends mostly on:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
What’s included?
- 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
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Welshpool
Powys is largely rural, with stone farmhouses and cottages under slate roofs, and timber-framed black-and-white buildings in Montgomeryshire towns near the English border. Brecon has Georgian streets, Llandrindod Wells has Victorian spa-town villas, and towns such as Newtown and Welshpool mix older centres with post-war and newer estates.
Stone and timber-framed homes need breathable lime finishes and careful roof repairs. Rural homes commonly take extensions, porches and driveways, and town terraces suit loft conversions and window replacement.
So when we survey a Welshpool property for a double-storey extension, the first step is working out how it was built and what has been changed since.
Permissions for a double-storey extension in Welshpool
Planning law differs across the UK. For a home in Welshpool, it is the Wales rules below that count, and we check them with the council ahead of any quote.
In Wales, two-storey extensions are tightly limited under permitted development, including distance to the rear boundary, so most need planning permission.
Building Regulations approval is needed in Wales, and the Party Wall etc. Act 1996 applies to work on or near shared walls.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
What happens after you get in touch?
Free site survey
A free survey comes first. It gives us what we need to price a double-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Your fixed price
After the survey we send a quote for a double-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 double-storey extension are in place before the first day on site.
The work itself
The job proceeds in the order set out in the programme, with dust and debris kept under control. Finally we tidy away, inspect the work together and pass the finished project over to you with its paperwork.
How we work
Questions about a double-storey extension in Welshpool
How much does a double-storey extension cost?
A typical double-storey extension of 30–40m² across both floors costs £55,000–£110,000, built to a plastered finish. As a rough guide, allow around £1,400–£2,600 per square metre plus fixed costs for groundworks, scaffolding and fees. The second storey usually costs less per square metre than the first, because foundations and roof are shared. Bathrooms upstairs and a complex roof add most. We confirm a fixed price after the survey.
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.
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
How much will a double-storey extension cost in Welshpool?
As a guide, expect to pay £55,000–£110,000 including VAT for a double-storey extension in Welshpool. That range is adjusted for Wales, which runs about 8% below 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.
Also covering areas around Welshpool
Welshpool and its SY21 postcodes are part of our coverage. Homeowners in Newtown, Oswestry and Shrewsbury can also book a free survey with us and receive a written price for their job.

