Extension builders in Cardiff

Firms in Cardiff who list single and double storey, side return and wraparound extensions, ranked by verified customer reviews and then distance. Nobody pays to move up this list, and a message goes to the one builder you choose.

Showing 1–1 of 1 builders for extensions in CardiffSorted by verified reviews, then distance. Never by payment.

Graft Heating & Building Services Ltd

TrustMark registered building firm in Cardiff offering extensions and kitchens and bathrooms.

TrustMark

Cardiff · 19 miRegistered company, not yet verified

Phone01685 376633Mention MyLocalBuilders when you call

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A two-storey red brick Georgian-style house with white sash windows, a dark blue front door and two tall chimney stacks, seen from the street in Manningtree, Essex — Photo by David Walker | Walker Design Co. on Unsplash (Unsplash Licence).

Before you contact a builder

Our guide to extension builders covers what the job involves, the approvals it needs and what to check before you hire. For prices, read House extension cost in the UK (2026 prices). Local planning, building control and housing notes are on the Cardiff page.