Background to seismic design aspects of the provisional New Zealand Code of Practice for Masonry Structural Design is given. Emphasis is given to reasons for differences in the provisional code from an earlier draft code. The changes include improved compatibility with the current Loadings Code NZS 4203 and the Concrete Design Code NZS 3101, provisions of simplified rules to ensure adequate ductility capacity, and additional information to provide guidance for ductile design of masonry frames. Some experimental results are presented to provide support for the provisions.