Two low energy houses having identical floor plans were built on adjacent blocks at Rokeby, near Hobart. They were built to demonstrate the technical suitability of north storage-wall passive solar heating. One wall was built of 300mm (12in) thick concrete whilst the other was built of water filled tubes. In both cases the storage walls had solar selective surfaces and single glass covers. Both houses were occupied by Housing Department tenants. Measurements taken over two years indicate a substantial improvement in thermal comfort and halving of the space heating requirements compared with that of an average Tasmanian house. It is concluded that north storage wall passive solar heating is ready for immediate implementation and that it has the advantage of being substantially independent of household behaviour. A demonstration videotape was produced.