  The indoor climate conditions of monumental buildings are very important for
the conservation of these objects. Simplified models with physical meaning are
desired that are capable of simulating temperature and relative humidity. In
this paper we research state-space models as methodology for the inverse
modeling of climate responses of unheated monumental buildings. It is concluded
that this approach is very promising for obtaining physical models and
parameters of indoor climate responses. Furthermore state space models can be
simulated very efficiently: the simulation duration time of a 100 year hourly
based period take less than a second on an ordinary computer.
