||Sustainable aspects are of increasing importance concerning the chances in the market, the reliability of performance, and the duration of the life cycle of buildings. Aside from their impact on the condition of the environment, sustainability serves primarily occupiers and tenants. This is of strong influence on the economical success of an investment. The question arises, why planning, constructing and running of buildings still lack of strategies that take sustainable criteria into account. Do the actors need more information about how to deal with such goals? Is there a problem of knowledge or of acceptance? But the reason can be suspected elsewhere. The commonly uses methods in the decision making process are not able to properly picture the chances and risks of real estate developments considering sustainable aspects. This paper takes a close look at selected techniques that are frequently used during the initiating process of a development. These techniques are for instance: the net present value method, the cost-benefit analysis and the real estate analysis. Decision-making is a constant task for all the actors during the whole life cycle of a building. Therefore it is reasonable to assume that there are a lot of decisions being made that counteract with sustainable strategies only because people don't have access to adequate means. This research project deals with the requirements for developing relevant methods and the impact on the users.