In the assessment of buildings thermal indoor climate in The Netherlands, the directives used are the ones given in 1979 and 1991 by the Government Buildings Agency (GBA). The criteria formulated in 1991 in the form of 'weighted excess hours, were a subject for debate. This article treats these directives and their backgrounds. Additionally, it contains information about a project started (September 2000) with as a goal to innovate these directives. This project is developed with the support of NOVEM and the GBA. On the one hand, it tries to improve and optimize the communication necessary with regards to the debates on backgrounds. On the other hand, it treats new notions about desired comfort temperature (Brager and De Dear). This focuses on the relation of the indoor comfort temperature with the outside temperature in the preceding 1 month period. The new criteria and assessment instruments will be presented in a ISSO-publication.