Have a look at this [https://www.gov.uk/guidance/buildings-and-construction-vat-notice-708#section8] think it has to be empty property officer
- Reduced rating the renovation or alteration of empty residential premises
8.1 The conditions
8.1.1 Introduction
If you carry out work to an existing building you will normally have to charge VAT at the standard rate. You may be able to charge VAT at the reduced rate of 5% if you’re renovating or altering either:
an eligible dwelling that has not been lived in during the 2 years immediately before your work starts (although there’s an exception explained at paragraph 8.3.4)
8.3 Rules for premises that have been lived in recently
8.3.1 The 2-year rule
You can only reduce rate the renovation or alteration if, in the 2 years immediately before renovation works start, the qualifying residential premises has not been lived in.
If the premises is a building (or part of a building) which, when last lived in, was 1 of a number of buildings on the same site used together as a unit for a relevant residential purpose, then none of the buildings making up the original unit must have been lived in during the 2 years immediately before your work starts. So you cannot, for example, reduce rate the renovation or alteration of a dormant building within the grounds of an operational home or institution.
8.3.2 Proof that the premises has been empty for 2 years
If you reduced-rated your supply, you may be required to show that the building has not been lived in during the 2 years immediately before you start your work. Proof of such can be obtained from Electoral Roll and Council Tax records, utilities companies, Empty Property Officers in local authorities, or any other source that can be considered reliable.
If you hold a letter from an Empty Property Officer certifying that the property has not been lived in for 2 years, you do not need any other evidence. If an Empty Property Officer is unsure about when a property was last lived in, they should write with a best estimate. We may then call for other supporting evidence.