I wouldn't say aeros between 1 and 2000 was particularly low but it does rather depend on the pilots skill level. Doing aeros over any type of buildings is most definitely bad form even if it is not strictly illegal, (glide free and all that).
It might be worth, calling on your neighbours during the next aeros demo, so they can see you are on the ground. Sugest to the pilot that doing it over the house is not good form and give him a copy of the CAA Good Sense booklet about Aerobatics.
If the ground he intends to land on is not suitable, it will nly be a shourt time before he breaks the a/c so that will stop him anyway!