Insulating a prefab gargage

[Simonbradley86]

Hi, I have a prefab garage at my new property and I would like to insulate it so I can use it through the winter as an office.

My thoughts was to bitumen the back of the concrete panels to seal them all then to build a inner wall out of 3x2 treated timber about an inch away from the concrete panels with celotex cut between the timber uprights.

I was then thinking of putting foil backed plasterboard screwed to the studwork.

A) would this be sufficient?
B) is their a cheaper way of doing the same job?
c) would I need to put polythene or a breathable membrane between the studwork and plasterboard?

please can someone give me some advise.

 

[Deluks]

Your plan is doable, but heating and ventilation should be added into the mix. Don't paint the concrete panels, fairly pointless.
Build a single course of bricks around the perimeter and build the stud walls onto this.
Don't forget ceiling and floor too.

 

[Simonbradley86]

What is the best way to ventilate this room. I plan to have electric heaters on thermostats as my form of hearing.

Also could I not use Dpm under the stud wall as a cheaper alternative to laying bricks all around the room?

Thanks