garage conversion

[canny177]

Hi Guys,
I'm thinking of converting my garage into a playroom.
At the moment it consists of 4'block walls and concrete floor.
I'm planning to fix a waterproof liner to the walls, stud frame about an inch away from the wall, insulate with polystyrene sheets and line with a 12.5mm foil back plaster board and lay a damp proof sheet to the floor then lay polystyrene sheets -2 inch, then woodchip t&g flooring. so i have a floating floor. The ceiling will be insulated up to 300mm in thickness then covered with a 12.5 mm foil back board. then the room will be skimmed with plaster.
Do you think this is a decent way to tackle this project so in the future if the room is converted into a habitable room i will meet building regs requirements with minimal additional work needed.
What other ways could a waterproof the garage and will i need a vapour barrier on the outer side stud if using foil back plasterboard.;and if i do can i use the fabric roofing rolls now being used instead of the old roofing felt?
many thanks

 

[Deluks]

Using foil-backed plasterboard you will not need any other vapour barrier. The use of felts and membranes on the back of studwork is for timber frame and clad structures, you have 4" block walls so will not be an issue.

What are you going to do about the garage door?

 

[canny177]

Thanks Deluks,
Thinking of building up the opening and putting in a window to match the rest of the house.
Do you think my plans for the floor will be ok?i plan to bring the liner up and in front of the sheeting on the walls.
If i kept a gap between the wall and stud do you think foilback would do without the need for the waterproof barrier?There is no evidence of damp in the walls, only where the garage door is.