Calculating your landlord property insurance is done by your insurance company
, and while there are a number of ways of doing this, you don't have much say in the methodology. Basically, your insurance company takes the structure, age and use of the building into account and creates a rating for your building. This can then be translated into a risk rating for your property. Above all, make sure you're covered for any damage done by your tenants, and you should be okay.