Many thanks for your responses Mark and Nick, very useful.
A german friend has done a quick translation for us, and both your comments of PVHP's simplicity bear out, but I agree that it will be a good educational tool for colleagues to get them into the basics - attached our translated sheet for interest....(removed sheets that related to converting results to EnEv energy standards for simplification, so boiled down to only 6 sheets...)
Interested in the idea of pulling out graphs for heat loss, etc from PHPP, Nick - do you create a separate sheet with the data to create your charts? I'm currently not that well versed in creating graphs in excel, will have to give it a go.....
Many thanks, Jennie