TRESTRAIL & TRESTRAIL V BRIGGS  SASC 413
Supreme Court of South Australia – 24 September 1999
Briggs owned a block of land in the Adelaide Hills and retained Trestrail to construct a driveway to run from the northeastern corner of the land. Trestrail quoted a piece of $4000 to $4500 for the work.
Trestrail started the work but constructed the driveway to run from the northwestern corner of the land. When the works were well under way Briggs inspected the works and found out that the driveway was running from the wrong corner. After some discussions Briggs reluctantly accepted that the driveway would run from the wrong corner on one condition that a motor vehicle would be able to use the driveway. The corners on the driveway were too tight.
Trestrail sued for unpaid work and Briggs sued for breach of contract.
Did Briggs agree to a variation of the original contract?
Was Briggs estopped from claiming breach of contract against Trestrail?