For this part, a building contract is a
"subcontract" if—
(a) both the contracting party and the contracted party for the contract are building contractors; and
(b) for the contract, the contracted party is a subcontractor for the contracting party; and
(c) the building work the subject of the contract is the whole or a part of building work the subject of—(i) another building contract, under which the contracting party mentioned in paragraphs (a) and (b) is the contracted party; or(ii) a domestic building contract between the contracting party mentioned in paragraphs (a) and (b) and a consumer.