Indoor climate study in the ”heavy“ Golden Hall in Nuremberg and in the ”light“ glass enclosure of the Busmann Chapel in Dresden. On the basis of the simplified energy and moisture balance of a building the model and program CLIMT (Climate-Indoor-Moisture-Temperature) for the practicable calculation of the indoor air temperature and relative humidity has been developed. Moreover the climatic generator CLIG is an userfriendly program in order to generate binary climatic dates (hourly values of temperature, relative humidity, shortwave direct radiation on chosen freely surfaces etc.) The results have been validated with hourly values of measurements in actual buildings in Germany: The ”Golden hall“ below the ”Zeppelin terrace“ in renovation since 2015 by the city building department Nuremberg and the glass housing around the Busmann chapel replica in Dresden. The correlation between calculation and measurement of temperature and humidity is nearly perfect. That is important for the planning of rehabilitation measures and the using of both buildings as museal spaces.