I'm thinking of having a custom workshop/shed built, 14Ft x 9Ft.

The shed will be built with 3" x 2" framing with an apex roof. I will be
dealing with the insulation myself.

Which is the best method for this? fibreglass or polystyrene between the
framing and either plywood or un-skimmed plasterboard for the walls?

The finished interior will have an emulsion paint finish.

I suppose plywood would provide a better finish (no taped joints) but
plasterboard would be cheaper and easier to install.

Suggestions and opinions please.



PS

In an earlier thread someone mentioned insulating flooring from Costco
can anyone elaborate?