In the paper two simplified methods of building sustainability assessment based on quantitative and qualitative analyses are presented. The methods are spinoffs of the SBTool [1], first one was elaborated under the STEP project[2] performed at Warsaw University of Technology, and the second under the project NEW EXPERT [3] executed by Energy Conservation Foundation. The quantitative assessment is based on characteristic parameters for comparison between values for existing buildings and reference ones. Five factors are taken into account: energy use for heating, pollution emission, water use, waste production and building lighting. The second method: qualitative assessment is based on rating of areas and criteria for the environmental impact of building. The evaluation is done for five main areas: load on environment and environment aspects both based on LCA, outdoor, indoor environment and building economy based on assessor’s subjective opinion. Both simplified methods can be easily used by designers, architects and energy consultants for labeling of buildings and were elaborated in order to enhance their market offer.