"The Roof orientation can be defined by selecting the appropriate zone and roof envelope in 'Envelope details' (beneath 'Zone details'). The roof can then be assigned the appropriate orientation and divided into appropriate sections if required. If a zone has multiple roof pitches then multiple roof envelopes should be created to account for these pitches i.e. a single zone can have multiple roof envelopes (in a similar essence to walls). Up to two roofs can be created in 'Quick envelopes' for any zone, any number can be created using 'Envelope details'. The extent to which this is necessary should be clarified by your accreditation scheme.