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.
For a homeowner in Pontypridd, planning a double-storey extension tends to begin with two questions: what will it cost, and how disruptive will it be? Our guide range is £55,000–£110,000 including VAT, and a typical job runs to 14–22 weeks on site. Both numbers firm up once we have seen the property, measured up and agreed exactly what is included.
- Guide price
- £55,000–£110,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- CF37
- Planning rules
- Wales
- Local area
- Rhondda Cynon Taff
- Survey
- Free, with a written quote
What should you budget for a double-storey extension in Pontypridd?
These are guide costs, not quotes. For a double-storey extension in Pontypridd the range is £55,000–£110,000, VAT included, reflecting prices in Wales that are about 8% below the national guide. Once we have visited for a free survey, you get a firm figure for the scope you approve.
| Type of job | What it usually involves | Guide in Pontypridd |
|---|---|---|
| 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 |
The main things that change the figure:
- 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 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
- Windows, external doors, plastering and internal doors
Local housing and a double-storey extension
The Rhondda, Cynon and Merthyr valleys are lined with stone terraces built for mining families, stepped along steep hillsides. Pontypridd, Caerphilly and Merthyr Tydfil have Victorian centres, and Bridgend has grown with large modern estates alongside interwar and post-war housing.
Valley terraces commonly need repointing, roof repairs, rendering and window replacement, and loft conversions can add useful space. Newer estate homes often take garage conversions, porches and landscaping.
In Pontypridd, as elsewhere in Mid Glamorgan, we take the building's age and construction into account before recommending anything, because both can change what is involved in a double-storey extension.
Planning and building rules in Pontypridd
Each UK nation sets its own consent rules, and Pontypridd is in Wales. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
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.
From survey to handover
A visit to your home
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a double-storey extension, and photograph or measure anything the quote needs to reflect.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
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 Pontypridd property.
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.
What you can expect from us
Frequently asked questions
How much will a double-storey extension cost in Pontypridd?
As a guide, expect to pay £55,000–£110,000 including VAT for a double-storey extension in Pontypridd. 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 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.
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a double-storey extension, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
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.
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.
Near Pontypridd
We survey and quote throughout Pontypridd's CF37 postcodes and in surrounding places such as Tonypandy, Caerphilly and Gelligaer. The process and pricing approach are identical in each of them.

