Hi! Great question!
It is true that both zones and site limits can be used to define the area you would like to analyze.
However, site limits is also used for site area metrics. You may want to define the site limit based on the property boundaries.
We have also added the concept of zones, to enable you to draw any area you like. You may want to add a large circular zone and explore the effect of new buildings on neighboring buildings, or you could add smaller zones to focus on specific parts of the site.
Regards,
Hilde
Hilde Bakkeli
Product Manager