So you consider this house enemy? The attack is an act of despotism.At least Israel targets its enemies, whereas Hamas deliberately targets civilians. Israelis only get 15 seconds to run to safety when the siren sounds which is a lot less time that the knock on the roof. If you shelter Hamas, expect to get messages then the knock on the roof at any time.
Do you consider Israel your enemy, including the unarmed arab women and children. This is the answer to terrorism and war crimes that is fully proportional under the circumstances. The owners of the building can always demand compensation from hamas after they allowed the terrorists to fire from the building.