A review of the literature in the field of construction heat engineering and regulatory requirements for thermal protection of buildings is given. A study of methods of increasing thermal protection for reconstructed and designed buildings, taking into account modern requirements, has been carried out. A methodology for strengthening the thermal protection of building structures has been developed.

Keywords: thermal performance of building , energy efficiency, heat-efficient enclosing structures, thermal insulation materials

A study of the operation of the water heating system of the Naryshkin bastion of the Peter and Paul Fortress was carried out. The results of measurements of temperature and relative humidity of indoor air are presented. Based on the research results, a three-dimensional model of room No. 3 of the Naryshkin Bastion was built, which was used in numerical modeling using the STAR-CCM + hydrodynamic computer complex. Recommendations for improving the heat and humidity regime are given, prospects for further research of the object are identified.

Keywords: object of historical and architectural heritage, microclimate parameters, water heating system, thermal regime, STAR-CCM +