Act No. 183/2006 Coll., On Spatial Planning and Building Regulation (Building Act), as amended, requires in the objectives and tasks of spatial planning, section 18, paragraph 4, to determine the conditions for the economical use of the built-up area and to ensure the protection of unbuilt land and unstable land. This requirement is further elaborated in section 53, paragraph 5, letter f) in which it is stated that the justification of the land use plan is also an "evaluation of the efficient use of the built-up area and an assessment of the need for demarcation".

In the "Evaluation of the Exploitation of Use of Built-in Territories and Assessment of the Need for Land Settlement", published by the Institute for Territorial Development in 2008, it is stated that "the evaluation of the efficient use of the built-up area and the assessment of the need for demarcation are a highly professional activity requiring detailed knowledge of the conditions in the territory, the needs of the municipality and the preconditions for its development. "

Stable areas for housing, whether in the form of clean or mixed, are the largest measure of the need for stagnant areas in municipalities' plans. Their definition must be made in the light of the potential for development of the territory and the utilization rate of the built-up area, as required by section 18, paragraph 4 of the Building Law.

The potential for development of the territory is reflected primarily in demographic development both in municipalities and in wider regions. The rate of utilization of the built-up area by the dwelling is determined, among other things, by the ratio of inhabited and unoccupied dwellings in the municipality and the size of residential households. An important factor influencing the utilization rate of the built-up area is the decrease in the number of dwellings, which is currently reflected mainly in increasing the number of objects used for family recreation.

To estimate objectively the need for trapped areas in the municipality's municipal plan, it is necessary to prepare a population forecast in the municipality in the medium-term and to estimate the size of the dwelling loss and the decrease in the number of dwellings. These activities are highly specialized and can only be accessed with detailed knowledge of the patterns of demographic trends and trends in housing. The basis is mainly the results of the census of houses and flats and other specific data such as data on the size of the plots for family houses provided by the Czech Statistical Office (CZSO).

The URBANCA calculator was prepared in 2011 under the project "Regional disparities in housing availability, their socio-economic implications and proposals for measures to reduce regional disparities", which was part of the WD-05-07-3 research program of the Ministry for Regional Development. Three institutions, the Institute of Sociology of the Academy of Sciences of the Czech Republic, v. I., Institute of Regional Information, s.r.o. and the Department of Urban Engineering at the Faculty of Civil Engineering at the Mining University - Technical University of Ostrava, based in Ostrava. In 2013, the calculator was updated based on the final results of the 2011 Census of Homes and Dwellings, and on the basis of the CZSO's population records.

The URBANCA calculator contains data on population and occupied dwellings in municipalities at the beginning of 2013, an updated forecast of population growth in all municipalities in the Czech Republic by 2028, adjusted coefficients of the rate of dwelling loss and dwelling density, and newly recalculated data on average land size for new family houses. The calculator allows you to edit and refine these data according to the user's detailed knowledge and modeling of the municipal development options.

While using the calculator, it is possible to modify the pre-prepared data according to the current situation in the municipality and according to the specific expert ideas of the user. This concerns predominantly the estimated waste intensity of the dwellings and the long-term decline in the number of dwellings. The proportion of dwellings to be built in built-up areas by superstructures, build-ins, outbuildings, in vacancies, etc., needs to be specified in order to calculate the need for arable areas for housing. The expected share of dwellings on new plots should be determined taking into account the structure and possibilities of building a particular municipality.

The need for surfaces is also influenced by the share of new dwellings in residential buildings, which, especially in the cities, represents a significant item adjusting the resulting need for areas. The basic parameters are the average size of the family house (20% of the land on the service roads, protection zones, greenery, etc.) and the average size of the land for one apartment in an apartment house, which mainly reflects the average layout and claims for public surrounding areas including parking areas.

The last input is to set a reasonable reserve of land use plan that can cover the unexpected interest of investors in housing construction in the village and on the other hand creates a policy because most land is not completely sure at the time of the land use plan whether it will be offered for development in the next few years. The calculator does not include the balance of the second home.

Publication URBANCA to download (only in Czech language).