Acta Scientiarum Polonorum

An essay raises the issue of thermal modernization of historical buildings in relation to tightening the regulations
on energy consumption. Two storeys of multi-family housing adapted for office purposes were examined.
Calculation were made for three variants of thermal insulation from the inside – mineral wool on wood
frame, mineral insulation boards and polyurethane boards with plasterboard. All variants cover heat transfer
coefficient requirements defined in regulations for the years 2013, 2014, 2017 and 2021. The analysis was
based on the NPV method and is supplemented by the cost of the loss of usable space. An analysis of the
15-year period indicates, that thermo-modernization from the inside in the examine housings would not be
cost-efficient after tightening the thermal regulations in 2014, 2017 and 2021.