The need for the development of non-destructive methods for evaluating structural brickwork is outlined and different approaches to the application of NDE are reviewed. An approach based on the separate evaluation of the bricks themselves, the mortar and the most important variable in practice, the workmanship, is advocated. Anevaluation method usingchanges in ultrasonic pulse transit timeasa measure of variations in quality is developed based on a range of test data. The approach is shown to be capable of detecting potential construction errors, such as the use of under strength mortar or the incomplete filling of the mortar joints.