A loft conversion turns unused roof space into a habitable room such as a bedroom, bathroom or office, with a proper staircase, insulation, fire protection and natural light from rooflights or a dormer.
We take on a loft conversion throughout Caerphilly and the surrounding CF83 postcodes, as well as in Risca, Pontypridd and Gelligaer. The guide range for this work in Wales is £27,500–£60,000 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
- £27,500–£60,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- CF83
- Planning rules
- Wales
- Local area
- Mid Glamorgan
- Survey
- Free, with a written quote
How much does a loft conversion cost in Caerphilly?
Every figure below is a guide for a loft conversion in Caerphilly, inclusive of VAT. Regional pricing for Wales works out about 8% below the national guide, and the overall span is £27,500–£60,000. 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 Caerphilly |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £18,500–£32,000 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £29,500–£55,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £46,000–£78,000 |
Your price depends mostly on:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Adding a shower room or en-suite in the roof
- Staircase layout, fire doors and the level of finishes
Scope of the work
- Structural calculations and steel beams where needed
- Dormer, hip-to-gable or rooflight structure as agreed
- Staircase designed to fit your landing and meet regulations
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
Building in Caerphilly
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.
So when we survey a Caerphilly property for a loft conversion, the first step is working out how it was built and what has been changed since.
Planning and building rules in Caerphilly
The notes below cover Wales, which is where Caerphilly sits. Rules change and every property is different, so we speak to the council before pricing your job.
In Wales, loft conversions and dormers can be permitted development within volume and position limits (for example, dormers on rear-facing slopes and set back from the eaves). Conservation areas and listed buildings need planning permission.
Building Regulations approval is needed in Wales, and the Party Wall etc. Act 1996 applies to work on 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
Free site survey
A free survey comes first. It gives us what we need to price a loft conversion 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
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 loft conversion are in place before the first day on site.
Finish and handover
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Common questions
Do you cover Risca, Pontypridd and Gelligaer?
Yes. As well as Caerphilly, we cover Risca, Pontypridd and Gelligaer and the rest of Mid Glamorgan. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Can you combine a loft conversion with other work?
Yes. Because we manage several trades under one contract, we can plan a loft conversion alongside other work on your Caerphilly home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Does the Party Wall Act apply to a loft conversion?
The Party Wall etc. Act 1996 applies in England and Wales only, and loft conversions on terraced and semi-detached houses often fall within it, because steel beams are usually set into the shared wall. You must serve notice on the neighbour before work starts, and they can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act. We tell you during the survey whether notices are likely.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £27,500–£60,000. A simple rooflight conversion costs less, while hip-to-gable and mansard conversions cost more because they change the roof structure. As a rough guide, allow around £800–£1,700 per square metre of new floor plus fixed costs for the staircase, steels and fees. Adding a shower room is the most common extra. We confirm a fixed price after surveying your loft.
Is my loft suitable for conversion?
A loft is usually suitable for conversion if there is enough head height, a roof structure that can be adapted and space for a staircase. A common rule of thumb is at least 2.2m from the top of the ceiling joists to the underside of the ridge, though dormers and mansards can create height where it is short. Modern trussed roofs need more structural work. We check all of this at the survey.
Also covering areas around Caerphilly
We survey and quote throughout Caerphilly's CF83 postcodes and in surrounding places such as Risca, Pontypridd and Gelligaer. The process and pricing approach are identical in each of them.