Whats the best insulation for a wooden garage

Thanks for looking, hope some helpful advice will follow my plea.....!!

I have just errected my wooden garage, 16foot by 9foot.... Im going to be using as my office/workshop for my clothing company to begin with, therefore i will need to insulate....

What is the best way to go anout this.... I am about to put in a standard chipboard tongue and groove floor then planning on insulating the walls and roof possibly covered with plasterboard?

This is where i am unsure of the best method to proceed and keep the cost down as i am a small business starting up i want to do it right but also keep costs low...

Any advice here will more than welcome...

50mm foil backed kingspan?

Kingspan or Celotex or similar, and as thick as possible. You should also insulate the floor.

Rockwool or fibreglass quilt will be cheaper per m2, but less efficient for a similar thickness of Celotex/Kingspan. But use fibreglass above the ceiling - 250mm if you can

Don't forget some ventilation to the room and the roof space if you form one

And seriously consider fire protection work - ie 1/2" plasterboard and skim, means of escape and a smoke alarm - linked to the house. And protected sockets, proper lighting and a suitable fire extinguisher.

It sounds like you are not bothering with building control then? Well just make sure its done right and is safe.

And lets not mention buisness rates shall we? Well, not until you make some profits