Describes the housing development comprising 224 apartments in three courtyards built in 1908. Provides a detailed description of the thermal modernisation measures and their monitoring from 1974 to 1982, permitting the systematic observation of the situation before, during and after modernisation. The present report concentrates on the measurements carried out from June 1980 to the end of May 1982. Four of the apartment buildings each containing 10 apartments were treated as test buildings with experimental energy conserving installations and constructional measures.