The primary advantage of the more detailed and thus more advanced method (holistic approach) is the higher quality and reliability of the results, due to the very realistic model on which the calculation is based. The intermediate results are quite exact and very appropriate for further more detailed analysis. Its main disadvantages are the need for suitable computer software for the complex calculation and the longer time required to perform the calculation.
The advantages mentioned above represent the disadvantages of the simplified approach, which uses a very approximate model. Nevertheless, the results can definitely be used to assess and compare the energy performance of simple buildings with conventional performance. The advantages of the simplified approach are the shorter time required to perform the calculation, and the fact that it can be done by hand.
More information: CENSE Information Paper P095 which can also be downloaded from the BUILD UP Portal.

Question submitted by: Dick van Dijk (TNO, The Netherlands)
Anwered by: Anna Staudt and Hans Erhorn, Fraunhofer Institute of Building Physics (Germany)
Date: 2008/02/04