For paragraph (b) of paragraph 1(6) of Schedule 10 to the Value Added Tax Act 1994 substitute—

“(b)

the value of the supply shall be taken to be such amount as is obtained by using the formula—

$\mathrm{A}\times \genfrac{}{}{0.1ex}{}{\left(10-\mathrm{B}\right)}{10}$

where—

• A is the amount that yields an amount of VAT chargeable on it equal to the VAT which would have been chargeable on the relevant zero-rated supply (or, where there was more than one supply, the aggregate amount which would have been chargeable on them) had so much of the building as is mentioned in sub-paragraph (5) above not been intended for use solely for a relevant residential purpose or a relevant charitable purpose; and

• B is the number of whole years since the day the building was completed for which the building or part concerned has been used for a relevant residential purpose or a relevant charitable purpose.”.