The Danfoss Leanheat Building is an AI based software and control system applied as part of the smart control of the building level heating system. The installed system upgrades the traditional principle of a static preset relation between the heating system supply temperature and the ambient temperature, the so-called weather compensations principle. The Danfoss Leanheat Building solution includes an adaptive dynamic building model in combination with weather prediction and measured apartment indoor temperatures. In this way, the optimal heating supply temperature can be estimated at a given time without compromising the comfort, taking the passive thermal storage capacity of the building into account, as well as solar radiation, wind, and ambient temperature predictions.