Best Stud Wall Insulation

[mikeym]

I`m building a dividing wall with a doorway across my integral garage to split it into two rooms, a dining room and a small storage area at the garage door end.
After a site visit the LABC officer tells me the main criteria to meet will be the thermal insulation values of the new habitable room. They cant advise what is the best material or give me any tech info re values to be acheived (at this stage).
What i`m asking here is taking into account that one end of the garage has a steel garage door, what is the best insulating material to use? How does polystyrene slab compare to the rockwool type material?
Also does anyone have any info re the best type of internal door to install for heat retention etc? I am advised that a fire door will not be necessary.
Any info appreciated.
Mike

[stoneyboy]

mikeym,
Assuming you are constructing a timber stud wall use Rockwool - your supplier will advise the thickness needed.
A fire door will give the best insulation unless you have a special made.
end

[eljaybee]

The U-vaalue that you need to achieve is 0.3W/m2K the same as for an external wall.

I recommend the use of a polyurethane insualtion (eg kingspan or celotex, the type with silver layers on surface) - it give better thermal performance compared to the same thickness of polystyrene or quilt.
Plus you don't have the possibility of the insulation slumping down which can occur with outher forms.