The paper discusses thermal quality improvement in historic buildings. It is based on a case study of a wooden historical building in an architectural style typical of Zakopane, located in the Podhale region of Poland. The building’s historical value and timber structure prevent the application of typical thermal retrofitting solutions. This paper presents an analysis of the possibilities of the improvement of energy performance of a historic building (villa) which included: a review of the available energy performance improvement solutions applicable to this type of building, with a particular focus on applying internal insulation; a technical condition assessment using non-invasive methods, the identification of problematic areas in terms of the thermal retrofitting of buildings with timber walls and decks; in situ tests: thermovision tests which showed the places with temperature distribution field disturbances in the building’s envelope, focusing on thermal bridges; measurements of actual thermal transmittance coefficients for extant partitions; measurements of the building’s airtightness and the microclimate in selected rooms; numerical analysis: an assessment of the influence of the thermal bridges on the building’s existing condition, an analysis of water content changes in wall systems post-insulation. The presented approach enables the improvement of the energy performance of timber historical buildings while preserving the historical value of its architecture. It is innovative because it tries to fill in a research gap concerning a lack of relevant guidelines in Poland. The research questions that the authors asked were as follows. Is it possible to improve the thermal insulation of a building’s wooden walls without adversely affecting the building’s technical condition? With regard to the necessity to meet nZEB (nearly zero energy building) standards, is it feasible to improve the timber walls of historical buildings? The study found that under the correct assumptions and while maintaining a responsible approach to design, it is possible to improve the energy performance of historical buildings without interfering with historical heritage.

Based on modeling and measurements, the authors investigated the performance of expanded polystyrene and lightweight aerated concrete slabs. The objective of the work was to assess the performance of the brick wall (having various thickness and layering) commonly built in the Silesia Region (Poland) in the 1920s and the changes of water content in layers of the flat wall through the measurement of temperature and relative humidity in the selected layers of the masonry wall.

This paper presents a proposal for a historic building thermal diagnostics algorithm for the example of a historical townhouse located in Lviv, Ukraine. The authors proposed a testing and diagnostics procedure that should precede design and renovation work associated with improving the energy standard of the buildings under discussion. The procedure was presented using a case study of a selected historical building. The scope of the study included an assessment of the building’s technical condition, thermal vision diagnostics, wall moisture, and water absorption in the context of protection against rain. Sample thermal and hygrothermal calculations were performed for a sample architecture element. The calculations included simulations of partition envelope behaviour after planned thermal retrofitting had been carried out. Performing the presented thermal diagnostics methods in three interlinked blocks (A, B, and C) shall ensure the proper thermal retrofitting of historical buildings in the context of their further occupancy.

The paper presents the results of in-situ research studies and hygrothermal simulations for a fragment of prefabricated cellular concrete wall, insulated with Styrofoam, allowing for two types of external plasters. The disruption of heat and mass transfer is effected by the connector for thermal insulation mounted in the layer of cellular concrete. The carried out research studies and simulations have demonstrated that the impact of the insulation connector with a steel core is observed only locally, but its destructive impact should not be ignored.

The paper presents the problems connected with preserved examples of buildings in Upper Silesia that contain the elements of half-timbered walls. This type of construction currently characterizes houses of various utility functions. Often, their formation was related to the construction of patron settlements, accompanied by the development of industrial plants. Today, there is a problem of insufficient thermal insulation of barriers in half-timbered houses and numerous attempts to improve their thermal parameters are observed. In this type of projects, the correct determination of the existing state in terms of construction of the barrier and thermal protection seems to be important, as the starting points for further analysis. The study determines the insulation of frame walls with ceramic fill, with a variety of material and construction solutions. Literature examples and in situ measurements results were used for the research