These systems are essential in homes built with very low leakage – often generically referred to as “eco homes” or “solar-passive” homes. The external envelope of these homes is typically very well sealed such that the passive ventilation is very poor. Balanced pressure systems are a specialist product that need to be precisely calibrated for each home. Installing such a system in a “normal house” is typically a waste of money. If you are building a well sealed home and do not install one of these systems in the building phase you will find it extremely difficult to retrofit. These systems are essential when building to high BAL or fire rated requirements. Not installing a system in these circumstances is simply foolish.