In analysing these elements, it can be seen that no building element which forms the envelope of the heated space meets the conditions laid down by law (measured by the transmittance coefficient). the design is a reconstruction of the entire envelope of the whole envelope comprising five construction measures (walls on the front of the building, ceilings over the outer space, replacement of an external joinery and which has not yet been replaced (roof windows), isolation of the flat and inclined roof and isolation of the wall in the ground), and an existing light distribution in view of reducing energy input and harmful CO2 emissions. The project also provides for the separation of measurement points (electricity, water), which must comply with the technical standards in force and standards.