This study focuses on the importance to reduce the energy consumption when buildings are reconstructed, in order to decrease the environmental impacts. When reconstructing/renovating buildings it is important that the actions taken result in buildings with both low energy consumption and a good indoor climate. It is also important that all parts involved in the building process are aware of the close relationship between the use of energy in buildings and the indoor climate. This paper describes the actions taken in order to save energy when some buildings built between 1966 and 1970 in Halmstad, Sweden, were renovated/reconstructed, and how these actions have influenced the indoor climate. © Copyright 2013 Elsevier B.V., All rights reserved.