Loft Conversion Cost in Belfast: 2026 Price Guide

• Rooflight (Velux) conversion: £17,500-£30,500
• Rear dormer conversion: £30,500-£45,000
• Hip-to-gable or mansard: £45,000-£68,000+

Building Regulations (Northern Ireland)

Loft conversions in Belfast need to meet Building Regulations (Northern Ireland), a separate set of standards from the rest of the UK, administered by Belfast City Council's building control service - always confirm current requirements directly rather than assuming an England-focused guide applies.

Party walls on Belfast's terraces

Most loft conversions across the Holyland, Sandy Row and similar terraced streets involve a shared party wall - though Northern Ireland doesn't operate under the Party Wall etc. Act 1996 that applies in England and Wales, so the legal process for agreeing shared-wall work with a neighbour differs and is worth clarifying with a builder or solicitor familiar with NI property law.

Rear dormers stay the practical default

A rear-facing dormer not visible from the street is generally the simplest option to get approved across most of Belfast's terraced streets, much as elsewhere in the UK - the main exception being inside a conservation area, where even rear alterations can face closer scrutiny.