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Irish Building Regulations: One National Rule Book
Ireland builds to one national set of Building Regulations, explained in the Technical Guidance Documents (TGDs) — no regional variations to track. This hub carries the numbers from the TGDs and the calculators that solve them.
Rules by topic
The parts of the code a chippie actually sets out — each one in plain English, with the numbers and a calculator.
Footings & slabs
Room heights
One rule book for the whole country
Ireland has one set of Building Regulations, and they apply the length and breadth of the country. There is no county-by-county or council version — whether you’re building in Dublin, Cork or a one-off rural site, the same national Regulations apply. Every building control authority checks your job against the same rule book.
The Building Regulations are made under the Building Control Act by the Department of Housing, Local Government and Heritage. They set out what a building has to do — stand up, keep people safe, keep the weather and damp out, ventilate properly — but the Regulations themselves mostly don’t carry the exact numbers.
Where the numbers come from
Most of the numbers a chippy sets out on site come from a Technical Guidance Document, or TGD. Each TGD is the Department’s guidance on how to meet one Part of the Regulations — Part K for stairs, ramps and guarding, Part A for structure, Part M for access, Part F for ventilation, and so on. Build to the guidance in a TGD and it’s treated as the deemed-to-satisfy route: the building control authority accepts it without argument.
A TGD is the standard path, but it is not the only legal path. A designer can instead show, by other means, that the actual requirement in the Regulations is met — an alternative design, backed by calculation or test. So treat the numbers on these pages as the normal, safe route, not the only one allowed.
One more thing worth knowing before you rely on any figure: the TGD edition in force can vary by the date a job was commenced or given permission, and older editions of some TGDs still circulate online alongside the current one, with different numbers. Always confirm the current edition on gov.ie before you sign off on a job.