Just a guide for you. I did up my ultra-old apartment with concealed wiring, cost is as follow: - Power socket - S$120 each (1 or 2-gang same price) - Lighting point - S$70 each - Ceiling fan - S$70 each So, my total concealed re-wiring bill for whole house power sockets, 13A + 15A lighting points, ceiling fan, 4xSCV, OpenNet came up to be high S$4K+. If I do exposed trucking, I think max S$2.8K.