What VAT rate is work charged at, and is that covered by the voucher? 

VAT on the installation of many energy-efficiency measures is not necessarily charged at the usual 20% rate. Instead, installers can, in many circumstances, charge 5% VAT, if both their customer and the installed measure qualify.

Installers will provide quotations and will show which elements of their installation are charged at the lower rate, and which are charged at the normal rate.

The installer usually has to buy the materials at the higher rate, but they can claim that back when they sell at the lower rate. The 5% rate is available on the installation of all the primary measures in the Green Homes Grant Scheme and most, but not all, the secondary measures.

Installations paid for by contributions from landlords do not qualify for the reduced rate.