When the height of the main house guttering that you are attaching to is 2.3m or lower.

The reason for this is once you install the permitter beam underneath the main home gutter you automatically lose 120mm then when you install our veranda roof you lose a futher 20mm per 1m of width.

Example if you have a vernada roof that is 5m wide you lose a further 5x20mm therefore 100mm.

The aim is to not have the permitter beam that is furthert away from the attachment point/house you are attaching to, to be lower than 2m high.

You will need a riser every 1.5m of attachment area.