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.
We take on a double-storey extension throughout Glyn-neath and the surrounding SA9 postcodes, as well as in Aberdare, Rhondda and Maesteg. The guide range for this work in Wales is £55,000–£110,000 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £55,000–£110,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- SA9
- Planning rules
- Wales
- Local area
- Powys
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Glyn-neath?
Here is how the guide price for a double-storey extension breaks down in Glyn-neath. We start from national figures and adjust for Wales, which comes out about 8% below the national guide. The resulting range, VAT included, is £55,000–£110,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Glyn-neath |
|---|---|---|
| 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:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Scaffolding duration, access and the level of finishes
What does the job include in Glyn-neath?
- Groundworks, foundations and below-ground drainage
- 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
- Electrics, plumbing and heating by qualified trades, with certificates
- Building control inspections and completion certificate
Building in Glyn-neath
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.
That variety is why a guide price for a double-storey extension in Glyn-neath is only a starting point; the survey shows what your particular property needs.
Do you need permission in Glyn-neath?
Which rules apply depends on where you live. For Glyn-neath, the answer is Wales, and the points below reflect that; we verify them with the council before quoting.
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
We look at the job
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.
Price and scope agreed
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Plan and prepare
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.
Finish and handover
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.
Why homeowners choose us
Questions about a double-storey extension in Glyn-neath
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.
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.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
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.
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.
Nearby towns
If your address falls within SA9, we cover it. The same goes for neighbouring Aberdare, Rhondda and Maesteg, which we include alongside Glyn-neath when arranging surveys and quotes.