Attic Conversion Costs in Ireland: What to Budget in 2026

An attic conversion is one of the best ways to add space and value to your home. Here's what you need to know. Average costs in 2026: - Basic storage room: €10,000 – €15,000 - Bedroom conversion: €15,000 – €25,000 - Bedroom + en-suite: €22,000 – €35,000 - Dormer extension: €30,000 – €50,000 Planning permission: Most standard attic conversions are exempt from planning permission, provided the converted floor area does not exceed 40m² and the roofline is not raised above the existing roof height. However, dormer windows facing a public road typically require planning permission regardless of size. Always check with your local authority or architect before starting work. What's included in a typical quote: - Structural assessment - Staircase installation - Insulation and plasterboard - Electrical wiring and lighting - Velux windows - Flooring - Building regulations compliance cert How long does it take? Typically 4-8 weeks from start to finish. Value added: A well-done attic conversion can add €30,000 – €60,000 to your property value — often a strong return on investment. Source: Costs based on contractor quotes and SCSI data. Planning exemption rules per Planning and Development Regulations 2001 (as amended).