Works that result in a change in the number of dwellings within a building (or part of a building)  can qualify for the 5 per cent rate. Hence, for example, converting an office into apartments or a house into flats (or flats into a house) or into a “relevant residential purpose” building all qualify for the 5 per cent rate.

The 5 per cent rate also applies to works of renovation or alterations carried out on a single household dwelling that has not been lived in for two years or more and to a building which is to be used solely for a “relevant residential purpose” or a multiple occupancy dwelling, provided the premises has not been lived in for at least two years.

For further information see Chapters 7 & 8 of HMRC VAT Notice 708: Buildings and Construction.