I have a mountain ash/rowan tree growing very close to the side wall of my house.Will it do any damage to my property

This is not a huge tree but should still be watched. Ask a good tree surgeon if unsure. By 'close' do you mean inches or feet?

How big is the tree? If it's still very young, move it (in autumn or winter) or remove it now. If it's already quite big, beware; removing it could upset the moisture content of the soil around your foundations causing subsidence in the most severe cases. This is most likely to be a problem if you are on a clay soil, which are more prone to shrinkage than other sorts of soil. IF you've got a biggish tree, just maintain the status quo and reduce the crown every now and then to stop it getting any bigger.