Reduced rate VAT on empty Grade 2 renovation

Hi, am renovating a Grade 2 listed Victorian School building to a residential use. It has been empty for over 2 years and is now being restructured from just the shell of the building, with an extension being added. As such it seems to qualifie for reduced rate. How do I go about getting necessary documentation to give to my building contractors so they can use the reduced VAT rate on their invoices?

Hi,
You can see the guidance here:
Reduced rating the conversion of premises to a different residential use
The building contractor would need to be satisfied that it has not been used as a dwelling and in most situations this would be obvious and would not require evidence.
Thank you.