"Two-storey extensions in Dublin are permitted under exemption ONLY if total combined floor area does not exceed 40m², first-floor walls are at least 2 metres from opposite boundaries, and rear garden retains at least 25m². Extensions exceeding these dimensions require full planning permission."
In mature Dublin suburbs like Rathgar, Terenure, Clontarf, and Mount Merrion, growing families frequently require both ground-floor living space and an additional first-floor master suite or home office. A two-storey extension provides maximum square footage on a compact site footprint.
Under Irish building law, any upper-floor window or external wall of an extension must maintain a minimum distance of 2.0 metres from the opposite rear or side site boundary to protect adjoining privacy.
A standard two-storey extension in Dublin in 2026 costs between €2,400 and €3,200 per square metre (ex. VAT), meaning a 60m² double-storey build typically ranges from €190,000 to €280,000 turnkey.
Consultations conducted Monday to Friday across South Dublin, North Dublin, Kildare, and Wicklow. Guaranteed itemized fixed-price RIAI tenders.
