Loft Conversion Cost in Cardiff: 2026 Price Guide

• Rooflight (Velux) conversion: £18,500-£32,500
• Rear dormer conversion: £32,500-£47,500
• Hip-to-gable or mansard: £47,500-£71,000+

Cardiff's terraced roof stock

The Victorian terraces across Roath and Cathays typically have steeper roof pitches than later housing, which can mean less dormer volume is needed to hit a comfortable head height - useful when Wales' own permitted development rules, distinct from England's, set the volume limits that apply.

Party walls

Most loft conversions on Cardiff's terraced streets involve a shared party wall, meaning a Party Wall Agreement with neighbours is required before work starts under the same UK-wide Party Wall etc. Act 1996 that applies regardless of the separate Welsh planning system - budget several weeks for this.

Pontcanna and conservation status

Inside Pontcanna's conservation area, even a rear-facing dormer not visible from the street can face closer scrutiny than the same job elsewhere in Cardiff - worth checking your property's specific status with Cardiff Council before committing to a design.