The IEA project Annex 27, Evaluation and Demonstration of Domestic Ventilation Systems,have come to the stage that simplified tools can be presented in a total scheme. At earlierAIVC conferences some of the tools have been presented in separate papers and still the toolsare under development. In this paper a more general approach of the usage of the tools is to bepresented.The work is based on the joint work of participants from both AIVC countries (CAN,F, NL, S, UK, USA) and non-AIVC countries (I, J). The tools that are to be used are forindoor air quality, energy, noise, thermal comfort, life cycle cost, reliability, and building anduser influences. A flow chart has been developed and is the procedure for the usage of thetools. The simplified evaluation tools are giving results both in a qualitatively and aquantitatively way. It has been applied on the four basic ventilation systems: adventitious,passive stack, mechanical exhaust, and mechanical supply and exhaust.