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.
Our guide for a double-storey extension in Wales comes to £55,000–£110,000 with VAT added, and that range applies across Powys, including Newtown, Brecon, Welshpool and Glyn-neath. Your own price depends on the size of the job, the specification and how easy it is to work on the site. We survey for free, check any consents needed under the rules in Wales, and then put the price in writing.
- Guide price
- £55,000–£110,000 inc VAT
- Time on site
- 14–22 weeks on site
- Planning rules
- Wales
- Price level
- About 8% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
Double-storey extensions prices in Powys
Below is a breakdown of typical costs for a double-storey extension in Powys. 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 Powys |
|---|---|---|
| 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 |
What moves the price up or down:
- 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
- Scaffolding duration, access and the level of finishes
What do you get?
- 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
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Building control inspections and completion certificate
Housing across Powys
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.
Upland weather dominates, with heavy rain, snow and hard frosts on higher ground, and remote sites can need extra planning for access and deliveries.
Do you need permission in Powys?
Homes in Powys come under the regulations for Wales, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
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.
The four stages
Survey and measure
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Quote in writing
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.
Plan and prepare
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 Powys property.
The work itself
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
What you can expect from us
Questions about a double-storey extension in Powys
How much will a double-storey extension cost in Powys?
As a guide, expect to pay £55,000–£110,000 including VAT for a double-storey extension in Powys. 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.
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.
Which postcodes in Powys do you cover?
We cover SY16, LD3, SY21 and SA9, along with the rest of Powys. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
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.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
Towns in Powys
Find your town below. Every place listed in Powys is covered for a double-storey extension, with the same survey, written quote and fixed-price process.

