This Technical Report specifies recommendations for the performance and design of ventilation systems which serve single family, multi family and apartment type dwellings during both summer and winter. It is of particular interest to architects, designers, builders and those involved with implementing national, regional and local regulations and standards.Four basic ventilation strategies are covered; natural ventilation, fan assisted supply air ventilation, fan assisted exhaust air ventilation and fan assisted balanced air ventilation. Combinations of these systems are not excluded and a ventilation system may serve only one dwelling (individual system) or