Attic conversion costs in Ireland depend on whether the space is being converted for storage or as habitable accommodation. A habitable conversion must satisfy building regulations for structure, stairs, fire safety, ventilation and insulation, and those requirements — particularly the stairs and fire protection — usually drive the cost.
The cost difference between a storage attic and a habitable attic room is significant. A habitable room requires a compliant fixed stair, structural strengthening of the ceiling joists to floor loading, fire separation and escape provisions under Part B, insulation and ventilation to Parts L and F, and adequate headroom.
Roof type matters. Traditional cut roofs are usually easier to convert than trussed roofs, which need structural alteration designed by an engineer. Adding dormers increases both cost and the likelihood that planning permission is required.