The subject of the following analysis is the Research Centre building of the University of Zilina (RC UNIZA), which was purposely designed as a low-carbon project. The measurements of selected offices were carried out to verify how the building envelope and infill cooling system influences the indoor environment during the summer season. These measurements, along with the parameters of outdoor climate and its influence on the indoor thermal-humidity microclimate were monitored. Most of the data was then used in subsequent transient-state thermal simulation in an ESP-r program. The evaluation took two days to complete wherein an air-cooling system and ceiling radiant cooling were presented. The office during the test was not occupied and was therefore slightly cooler. Under these conditions (measured and simulated), PPD and PMV indexes were calculated during a 10 h time period with varying input parameters (metabolic heat and thermal resistance of clothing). According to the measurement and simulation, these indexes were compared. The comparison shows that the agreement depends on the chosen personal factors such as the thermal resistance of the clothing and metabolic heat. If these are chosen appropriately, then the differences between the results according to the measurement and the simulation were limited.

The paper considers the issue of the thermal refurbishment of residential buildings built between 10 and 40 years ago in some European countries. It suggests that, while facade retrofitting is the most effective solution for older dwellings, all actions are equally less effective for newer dwellings built in this millennium. According to the current situation, as society shifts away from the use of fossil fuels, this paper presents the expected energy and financial savings that were calculated using one of four different heating sources. The study shows that the efficiency of the additional thermal retrofitting of the structures is low when the building is heated with a heat pump. The addition of thermal insulation to already well-insulated roofs or floors results in minimal savings of approximately 0.15 kWh per square meter of heated floor area per year. The potential advantage of replacing existing windows with new windows in a top thermal quality was shown. After window replacement, the financial benefits could be twice as high in houses heated by district heating compared to houses heated by gas or a heat pump, including an alternative heat pump with photovoltaics.

Current environmental crisis calls for sustainable solutions in the building industry. One of the possible solutions is to incorporate timber-framed constructions into designs. Among other benefits, these structures are well established in many countries, originating in traditional building systems. This paper focuses on experimental timber-frame walls. Different wall assemblies vary in thermal insulation materials and their combinations. We investigated ten experimental wall structures that have been exposed to natural external boundary conditions since 2015. The emphasis was on their state in terms of visual deterioration, mass moisture content, and thermal conductivity coefficient. We detected several issues, including defects caused by inappropriate realization, causing local moisture increase. Material settlement in loose-fill thermal insulation was another issue. Concerning was a significant change in the thermal conductivity of wood fiber insulation, where the current value almost doubled in one case compared to the design value determined by the producer.

Current building envelope greening systems are not just areas covered with vegetation. Today’s systems can maximise the functional contribution of vegetation to a building’s performance and become part of a sustainable urban renewal strategy. The impact of the vegetation layer directly affects the building in its immediate vicinity, from the outside, while also having a significant impact on the indoor environment. Green roofs are the most widespread vegetated structures worldwide. This paper aims to demonstrate the behaviour of the temperature regime of an extensive green roof over a production hall and an administrative area in comparison to that of a roof without vegetation cover. In evaluating the results, a period with weather representative of winter and summer was selected to show the importance of seasonality. The fact that this is a new building, and that the extensive roof is not fully covered with vegetation, is very well reflected in the results, as the absence of a vegetated area significantly affects the temperature of as well as the heat flux through the roof structure. The dark colour of the substrate absorbs significantly more solar radiation than the light surface of the waterproofing, resulting in an increase in temperature and heat flux into the structure.

Green façades with an active water regime and the water flowing through the substrate itself are not common. This system reduces the temperatures and incorporates the evapotranspiration, which could be more effective than by the regular green façades. The use of a double-skin façade with a ventilated air cavity can reduce the heat load, but the evapotranspiration can reduce it even more with additional benefits. Green façades could also serve as a key element for reducing the surface temperatures of the insulated metal panels (IMP), which are mostly used as a façade system for production facilities or factories. In this paper, a prototype of a double-skin façade, which consisted of vegetation board from recycled materials and IMP, is tested in a climate chamber to evaluate the function and benefits of such a combination. The outdoor skin is made from board, the surface of which is covered by the rooted succulent plants. Measurement results are represented as a direct comparison of single sunny day surface temperatures with and without a double-skin (green) façade. The use of the green façade reduces the indoor surface temperature of IMP by 2.8 °C in this measurement. The use of water circulation through the outdoor skin reduces the temperature of the vegetation board by 28 °C. This could have a great impact on the microclimate around the façade. Because of the controlled environment and ventilation system in a climate chamber, it is not possible to investigate the airflow and solar chimney effect within the ventilated cavity. In addition, it is complicated to show the potential of microclimate change caused by the wet vegetation surface. For the mentioned reasons, the need to carry out “in situ” tests on a model wall under the real conditions was indicated.

Improving the energy performance of buildings in the context of external climatic conditions and the requirements of indoor environments is a hot topic in the construction industry. It primarily concerns reducing the energy used for heating and cooling in buildings. In the EU sector, this is addressed by the Energy Performance Directive (EPBD), which is followed by relevant national standards. The energy performance of buildings is strongly influenced by the window structures that are part of the building envelope. Their influence on energy performance is represented by the heat transfer coefficient, which differs in the actual built-in window construction from the design value given by the manufacturer. In this paper, the authors deal with its measurement in situ using the heat flux measurement method. The measurement was carried out in the pavilion laboratory of the Department of Building Engineering and Urban Planning (DBEUP), Faculty of Civil Engineering (FCE), University of Zilina (UNIZA), on three window constructions of different material bases. During the measurements, surface temperatures on the glazing, heat flux density, and air temperatures were recorded in minute increments. The influence of the year-round cycle of the outdoor environment on the embedded window structures is presented and the results are presented in the conclusion of the paper.