Range from the cheapest single storey extension £36,600 (Building & Flat Roofing Contractors based in LL54) to the dearest single storey extension £47,000 (W F CLAYTON & CO LTD based in LL57).
Comparing extension builders estimates for fitting a downstairs toilet gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes to build a single storey extension in Holyhead by posting a job with HaMuch and we will send it to extension builders in Holyhead.

| Business name | Single storey extension cost |
|---|---|
| Glyndwr Roofing & Building Services, Holyhead, LL65 | £41,400 |
| Property Maintenance Solutions, Benllech , LL74 | £40,600 |
| Balmoral joinery/construction , Gaerwen gwynedd , LL60 | £41,880 |
| Hughes Construction, Bangor, LL57 | £41,720 |
| W F CLAYTON & CO LTD, Bangor, LL57 | £47,000 |
| Building & Flat Roofing Contractors, Caernarfon, LL54 | £36,600 |