Does anyone have an idea as to the cost and legality of installing a second toilet in the downstairs workshop area of a two story house in Brisbane? Its a non livable area (storage/workshop) Concrete slab and nothing there at present but it will go directly under the upstairs one and I would think simply go through the weatherboard wall and plumb into the existing toilet line. Water line is in the same area and I can easily throw up some pine frame, gyprock and swing a door. Plenty of ventilation provided by floor space/bearers exiting house. I have a trade background and can and have done general plumbing, building and some other's before and I know I can easily do this if its just a matter of tapping into existing pipes but "legally" I probably am not allowed.