In OECD countries, the residential and commercial sectors are responsible for 40% of the total primary energy consumption and for almost 30% of the greenhouse gases emitted from these countries (European Commission, 2010). In addition, the energy consumption in the building sector of these countries has had a continuous growth since the 1960s and is still increasing. Buildings’ energy use in OECD countries is mainly attributed to electricity, oil and natural gas usage. There are differences in energy use in buildings varying among countries. Economies in transition cover their buildings’ energy demands by using mainly natural gas and fossil fuels for district heating; while the share of renewable energy sources is low. The picture is very different for developing countries where energy needs in buildings are deriving from biomass and specifically wood, crop waste and animal wastes. The continued use of biomass for household energy needs has its problems too. The use of wood biomass results in deforestation and desertification and reduces the capacity of existing carbon sinks to absorb CO2 emissions (IEA, 2011). Furthermore, in developing countries, kerosene and paraffin are used for lighting but they represent a small share of coal and oil products (UNEP, 2012).