Thank you for the swift reply. I will certainly look into a warm roof construction, however I am on a ridiculously small budget. As mentioned, the kitchen is tiny, therefore the difference in price may not be massive. I've no idea about insulated ply boards so excuse me if I'm writing rubbish...
Firstly an introduction. I have recently purchased a Victorian terrace, where at some time in it's life, the outhouse was turned into a tiny kitchen. I'm interested in DIY, however won't attempt to do large jobs myself, I just like to know and understand what and why my contractors decide to use...