Building advice

Extensions guides for Northern Ireland

Everything we have written about extensions, priced and researched for Belfast and the rest of Northern Ireland.

Extensions 5 Mar 2026 · 7 min read

How Much Does a House Extension Cost in Belfast in 2026?

What a single-storey extension actually costs in Belfast in 2026, with rates per square metre, a worked 25m² example and where every pound of it goes.

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Know the number before you ring a builder

Reading is one thing. Put your own dimensions into a calculator, get a costed range with every line broken out, then ask three local builders to price the same specification.

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