A communal ventilation system is acceptable as long as it meets the requirements in the HQM manual.
In terms of maintenance, if it is not possible for the home occupants to carry out system maintenance themselves due to the type of system installed we would need a statement from the professional designing the system stating this. Instead, any specified ventilation system requiring maintenance must be designed to allow building services engineers to easily complete the work in a safe manner in accordance with manufacturer’s instructions and any other safety regulations, to prevent systems becoming redundant or being unable to function to their designed intention.