The topic of this paper is a suggestion for an integrated design method which allows building designers to make consequence-conscious design decisions in terms of energy performance and indoor environment at the very early stage of the building design process. Energy performance and indoor environment have due to new increased regulatory demands become decisive design parameters in the building design process. In order to comply with the increased regulatory demands, we present an integrated design method which argues that the design of buildings must start on room level rather than total building level. The proposed method starts with the establishment of design goals, including goals regarding energy performance and indoor environment, followed by a building physical analysis of performance-decisive parameters. This analysis is used to establish a space of solutions from which the designer can obtain an overview of the consequences of their design decisions in terms of energy performance and indoor environment. Based on the space of solutions the designer can set up possible room designs which fulfil the design goals prior to the total building form giving. The possible room designs can be combined in to a number of overall building designs from which the best performing proposal can be selected and optimised. In this way the final building design will have an energy performance and indoor environment inherited from the room designs, thus fulfilling design goals in terms of energy performance and indoor environment. The method has been tested and evaluated in courses in integrated design at the Technical University of Denmark. Furthermore the method has been tested in real building projects. Based on the experiences gained through these tests, the proposed method has been adjusted and refined in order to become the preferred method for integrated design of low energy buildings with high quality indoor environment.