A builder agrees to build flats for a fixed price. Part way through, the builder runs into financial difficulty and the client, fearing late completion penalties under its own contract, promises an extra payment per flat completed. No duress is involved. Following Williams v Roffey Bros, is the promise of extra payment enforceable?

Correct answer: D) Yes, because the client obtained a practical benefit from the continued performance

Explanation

Stilk v Myrick held that performing an existing contractual duty owed to the promisor is not consideration. Williams v Roffey qualified this: where the promisor obtains a practical benefit or avoids a disbenefit, and there is no economic duress or fraud, the promise to pay more is enforceable. Additional work (as in Hartley v Ponsonby) is not necessary under the Williams v Roffey approach.