Spatial and time diversity of housing construction in Poland. Residential housing construction, as one of the most important elements of spatial development, a factor decisive for living conditions of residents, is the object of interest not only of architects, planners or local and state authorities, but increasingly also of geographers, who mainly analyze these issues in a spatial context. The article analyzes the development of construction in post-war Poland in three periods: real socialism, the transformation period and the last decade. The subject of the analysis is the number of completed dwellings/flats in total, by location (city, village) and by investors (housing cooperatives, developers, private constructors and others).

Persistent air pollution (SMOG) in large cities in countries based on energy and coal heating is a serious and growing problem. Improving air quality is currently the main challenge for the metropolises of Central and Eastern Europe. Despite intensive efforts, the average annual concentration of PM2.5 in this area exceeds the standard recommended by the World Health Organization (recommended standard – 25 μg). Data from environmental institutions show that, for example, in Kraków (Poland), the number of days with PM 2.5 concentrations drastically exceeding the permissible standards in the last year was 96. The article describes the method of controlling air purification in the apartment using automation devices, control software and applications available for smartphones, tablets and personal computers. The presented solution uses technologies that can use free (alternative) software, extending the functionality of devices and increasing the flexibility of the control system. The main goal is to maximize the comfort of home users and to minimize the cost of electricity consumption. Additionally, the existing air cleaning devices are adapted to the needs of the air cleaning control system.