Section 283 | Non-industrial part of building disregarded F1
From legislation.gov.uk
(1)This section applies if, apart from this section, but taking into account section 571 (parts of buildings etc.)—
(a)part of a building would be an industrial building, and
(b)part (“the non-industrial part”) would not.
(2)If the qualifying expenditure relating to the non-industrial part is no more than 25% of the qualifying expenditure relating to the whole of the building, the whole of the building is an industrial building.