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HMRC internal manual

VAT Construction

Zero-rating the construction of buildings: is a building being constructed: prefabricated buildings and building kits

For a building to be ‘constructed’ it need not be built entirely ‘on site’. Large components may be made ‘off site’ for assembly ‘on site’. At the extreme, the relocation of a whole building can be the construction of a building on its new site.

VCONST02550 provides guidance on whether the supply is made ‘in the course of the construction’ and therefore zero-rated.