Energy efficiency and renewable energy are considered to be the twin pillars of sustainable energy policy and are high priorities in the sustainable energy hierarchy. In this context of continuous improve of energy efficiency in buildings; each state has developed different national politics on this direction. The obligation of the EU Member States to assimilate the strategy proposed by Energy Performance of Building Directive (Directive 2010/31/EU) determined the local communities to find financial resources and strategies to stimulate and manage the investments in building sector in order to reduce the energy use and energy costs in buildings. Infrared thermography is an effective tool for engineers, architects and consultants. It can be used to evaluate the existing buildings and can provide critical information about a building's sources of energy loss. The article reports a study of planar infrared thermography measurements made in order to achieve supplementary information/data used to estimate energy efficiency in the case of a number of collective residential old buildings.