Results are reported from a detailed parametric study to evaluate the performance of a newly proposed hybrid solar housing development in Monymusk, Scotland. The development embodies solar collectors forming part of the roof structure itself and indistinguishable in appearance from the local vernacular, a new optimised solar roof collector system which combines both heating and ventilation functions and the ability to automatically switch between a range of heating and/or ventilation modes. Each dwelling unit was modelled using degree-day properties, and the thermal performance was simulated over a period of one year, based on expected occupancy and usage, and using meteorological data appropriate to the geographical location. It is concluded that with careful construction, good thermal insulation, moderate thermal mass and properly controlled ventilation, the collector system can meet the space and domestic hot water heating requirements almost entirely. The annual total heating bill, with full price electricity, could be less than £50 per dwelling at 1994 prices.