Polish economy is characterised by high energy intensity in all sectors. Energy used for heating purposes for municipal and co-operatives buildings is especially high. A lot must be done to reduce energy consumption. This paper presents energy conservation technologies that have started to be introduced in thermal modernisation and refurbishment of existing household stocks. The utilisation of new methods employing solar passive, solar active and other renewables is considered. Definitions of buildings with reduced energy consumption, low energy buildings and environment friendly buildings are presented and described. Remarks and recommendation for Polish low energy buildings are presented.