Free Tool · 60 seconds
Do I need planning permission?
An interactive check based on Ireland's exempted development rules — the same national tests apply no matter where you live. Tell us about the project and we'll show you the statutory criteria, the likely answer, and what to do next.
What are you planning to do?
Pick the option that best fits your project.
Your result
Pick a project and property type, then run the check.
The 40 m² rule
Class 1 of Schedule 2 lets you build extensions up to 40 m² without permission, counting all extensions added since 1 Oct 1964 — not just the new one.
Building Regulations still apply
Exempt from planning ≠ exempt from building control. You still need a BCMS commencement notice and an engineer's certification for structural work.
Section 5 Declarations
If you're unsure, a Section 5 Declaration costs around €80 and gives you a binding answer in 4 weeks. Cheaper than gambling on retrospective permission.
Got an answer? See what your project will cost.
Run a cost estimate →Long reads
Planning permission isn't the only constraint
BCAR compliance, Section 5 declarations, conservation areas and protected structures all sit alongside the planning question. The cost and extension guides cover how each one affects budget and timeline.
Renovation cost · 14 min
How much does it cost to renovate a house in Ireland in 2026?
SCSI Nov 2025 + CSO COPI data. Cost-by-scope / spec / region / room tables, the eight hidden costs nobody quotes for, BCAR / pyrite / mica risks, and the 13.5% VAT rate that catches 3 in 10.
Read the guideExtensions · 8 min
House Extension Cost Ireland 2026
Based on 150 real Irish extensions. Typical Dublin cost €48,000–€65,000 for a standard rear extension. Full breakdown, location adjustments, and a step-by-step checklist.
Read the guide