Please I need some advise. We have a house with n tile roof. It is a semi double story house.. We want to replace the tile roof with a concrete slab roof. The city planner after looking at our house plans, said we have double walls and it is okay to put concrete slab roof. What I want to know is, do we still need engineer to give us permission? We are not building on to the house, just replacing the roof. And if we need a engineer, does somebody have contact details of one neer Hibberdene please?