WC extension

Yes, an under-stairs cupboard can often be converted into a WC. There is no single minimum room size for an additional WC in an existing house, but around 800mm wide × 1,400mm long is a sensible practical minimum. An outward-opening or sliding door can help maximise space. The room will need adequate headroom, a small hand basin, ventilation and a compliant drainage connection. The existing space and location of the soil pipe should be inspected first. Welsh Building Regulations A straightforward conversion would normally cost approximately £2,500–£4,000, potentially rising to £6,000 if significant drainage, structural or electrical work is required. A site visit would be needed to provide an accurate quotation.