Vernacular residential buildings evolved according to the principle of "trial and error". It is assumed that this led to a climate-adapted construction method. For a long time, vernacular construction was neglected by researchers, although the percentage of these residential buildings globally amounts to about 90%. The aim of the PhD is hence the development of a methodological approach to assess the degree of adaptation of a building to the predominant climate. A method consisting of parameter analyses, hygrothermal building simulations and statistical models is being developed. Buildings from classical Roman times will be used as an example, since Vitruvius' work "Ten Books on Architecture" can be regarded as the starting point of architectural theory.