We have known for a while the implications of the Final Statement under a traditional form of building contract. In Crown Estates Commissioners v John Mowlem (1994) the Court of Appeal held that, subject to arbitration proceedings being commenced within the stated timescale, the Final Certificate under JCT 80 could be taken as conclusive evidence of the architect's reasonable satisfaction that the standards of workmanship and the quality of all materials were in compliance with the contract. The effect was that, prior to amendment 15 of JCT 80, the issue of a Final Statement meant that the contractor would be free from liability for defects in materials and workmanship.
However, with so much work in the industry being conducted using design and build forms, the application of Mowlem was unclear. We now have a decision dealing with the "conclusive evidence" defence under the JCT With Contractor's Design (1981 Edition) which applies the reasoning of the Mowlem decision to design and
