Loft conversions in Cardiff

Covering Cardiff

We work in Cardiff (CF10, CF11, CF14) and the places around it, including Whitchurch, Penarth and Caerphilly.

Homes in South Glamorgan

Across Wales you find valley terraces, coastal towns, rural stone houses and newer estates, so access, slopes and local materials all feature in the design.

What do you get with a loft conversion?

We start with the head height. You need roughly 2.2 m or more from the top of the ceiling joists to the underside of the ridge for a conversion to work without raising the roof. From there we design the staircase position, the type of conversion and the en-suite, and manage the whole build including fire safety and building control.

Loft survey and head-height check
Design drawings and structural calculations
New floor joists, steels and staircase

How much does a loft conversion cost in Cardiff?

Use these ranges to budget for loft conversions; the survey turns them into a fixed price for the agreed specification.

Loft conversions	Guide price incl. VAT
Rooflight conversion	£30,000 to £45,000
Dormer conversion	£50,000 to £90,000
Hip-to-gable with dormer	£60,000 to £95,000
Mansard conversion	£65,000 to £110,000

Planning and building rules in Cardiff

In Wales the planning rules, including what counts as permitted development, are set by the Welsh Government, and Welsh building regulations differ in places from England’s. We check both against your house before drawings are finalised, and handle party wall notices where needed.

Wales has its own loft and roof permitted development rules. Rear dormers within set volume limits are often allowed, but the detail differs from England's, so we confirm the current Welsh limits against your roof before the design is fixed.

What can change the price or programme?

Head height under the ridge decides whether a conversion is practical.
Fire safety rules can mean new fire doors on the floors below.

From first call to completion

Start with a conversation. A short call or the online form is enough for us to understand what you want to build.
Survey at your house. We look at the existing structure, services and access, and agree what the design needs to achieve.
Drawings, approvals, written quote. We prepare the design, apply for the approvals it needs, and give you a fixed price in writing.
Build and hand over. Our teams build to the programme, building control inspects, and you get the completion paperwork at the end.

Loft conversions: common questions

Is my loft suitable for conversion?

If there is about 2.2 m or more from the top of the ceiling joists to the underside of the ridge, it usually is. We check this at the free site visit.

How long does a loft conversion take?

Usually 6 to 14 weeks on site depending on the type.

How do I get a price for loft conversions in Cardiff?

Use the guide price tool for a ballpark figure, then book a visit for a fixed written price for the agreed specification.

Loft conversions in nearby towns

Learn more about loft conversions, or see every project we cover in Cardiff.