Dear Wouter,
The most important item on calculation procedures I like to change or add can be summarized by the words "transparency" and "harmonization".
"Transparency" means that a calculation procedure is not just a black box and that detailed methods are per se worse better than simple methods.
"Harmonization" in terms, definitions and symbols and in the General structure of energy performance calculation procedures will strongly help to get better understanding and more interaction in Europe on the subject. In this respect it is very important to bring together current research (EU, IEA) and standardization activities (CEN, ISO).
