Energy use in the built environment represents a large part of total energy use in Sweden and is oneimportant sector where energy conservation needs to be significantly improved in order to meet thenational implementation of the European goals. One key question that needs to be investigated in relationto these goals is the performance and implementation of passive or low-energy houses. This paperpresents results and an evaluation of a newly built house in an area with passive houses in Linköping,Sweden. Nine passive houses were built with the aim to be energy efficient, with an annual space heatingdemand of 21kWh/m2, and at the same time to have the same visual appearance as any other buildingin the surrounding area.This study evaluates the energy performance of a residential area with low-energy buildings basedon Building Energy Simulation (BES) (IDA ICE 4), and measurements from the real object. Both annualand hourly validation is performed using room by room modeling and internal heat gains. A novelapproach to internal heat gain modeling is presented using time-use data (TUD). The resultsshowpossibleimprovements in the design, the building envelope and in the heating control.