Capital Allowances Act 2001 section 21

Buildings

Section 21 excludes expenditure on buildings and certain building-related assets from qualifying as expenditure on plant or machinery for capital allowances purposes.

• Spending on constructing or acquiring a building cannot qualify as plant or machinery expenditure for capital allowances
• Assets physically incorporated into a building, or of a type normally incorporated in a building even if moveable, are treated as part of the building and therefore excluded
• Specific items listed in List A — including walls, floors, doors, mains utility services, waste and drainage systems, lift shafts, and fire safety systems — are always treated as part of the building
• Section 23 provides exceptions that can override this exclusion, but items listed in Section 23's List C as "plant" do not include anything already excluded by section 21