The principle of the program is as follows.

The section of the urban planning space for which the calculation is to be performed is modeled in a reduced three-dimensional form in the graphical editor of the program, i.e. a computational scene is created. As a basis for its construction, a background (graphic file - general plan or topographic survey at a scale of 1: 500) is used, which is loaded onto the horizontal plane of an empty scene. Sets the direction to the north and the scale of the scene. Then the contours of the objects are traced on the background with the mouse and their heights are set, as a result of which the flat contours are stretched and turned into three-dimensional objects. Points are placed on the walls of the created design buildings, corresponding to the centers of the design windows. For each window, parameters are set that simulate its window opening (balcony, loggia, etc.), as a result of which the program automatically calculates the real point of insolation calculation for each window.

On such scenes, the calculation of the insolation of buildings is limited only to the calculation of the insolation of their windows (without calculating the insolation of rooms and apartments), and the calculation of KEO cannot be performed at all. Therefore, for situations where it is required to determine the observance of insolation standards in rooms and apartments, or to calculate the KEO of premises, the program has the ability to create more complex objects and group them into libraries. The principle of creating library objects practically coincides with the principle of constructing computational scenes. Objects are created floor by floor, floors are built on the basis of substrates (floor plans of any scale), along which the contours of apartments and rooms are outlined and design windows are placed. The points of calculation of the KEO are set in the rooms, for this the user only needs to set the necessary properties of the rooms, and the program will calculate the position of the points of calculation of the KEO independently (the position of the point of calculation of the KEO depends on the type of room - living room, office, etc.). At the final stage of construction, a parapet or a roof can be created for the object. Finished objects are saved to libraries, from which they are then imported to the design scene. Creation of libraries containing typical, often used in calculations, objects (buildings or sections of buildings), as well as the ability to exchange ready-made libraries between users, significantly accelerates the process of constructing computational scenes.

To calculate the insolation of territories on the scene, calculation areas of arbitrary shape are set, which is a grid of calculated points.

The finished scene is loaded into the calculation module, where the insolation and KEO calculations are made.

To calculate insolation, the calculated parameters are set: geographic coordinates and, in accordance with them, the calculated date, norms of insolation duration, etc., established by SanPiN 2.2.1 / 2.1.1.1076-01. Then the calculation is started, which is performed in the interval from the moment of sunrise plus the period not taken into account after sunrise until sunset minus the period not taken into account before sunset (the time not taken into account is set according to SanPiN 2.2.1 / 2.1.1.1076-01). For each minute within this interval, the program calculates the position of the Sun and determines the shading of each calculated point by the window opening and objects in the scene, summing up the illumination time. At the end of the calculation, the implementation of the insolation standards for windows, as well as for rooms and apartments of library houses, is determined in accordance with SanPiN 2.2.1 / 2.1.1.1076-01.

The calculation of site insolation is performed for each point of the site according to the same scheme as for windows. At the end of the calculation, the number of points is determined, the duration of insolation of which corresponds to the norms (if at least half of the points are insolated, the site is insolated).

Before calculating the KEO, design parameters are also set: for example, the administrative region (intended for standardizing the KEO). Then, the calculation starts, which is carried out according to the following principle. The window is split into equal parts horizontally and vertically, that is, into equal rectangles. A ray is drawn through the center of each of the rectangles from the point of calculation of the KEO and it is determined whether this ray intersects other buildings. If the beam does not cross the building, then the program calculates the geometric KEO from a part of the window (taking into account the MKO sky), otherwise the geometric KEO of the facade of the opposing building is calculated. Thus, the program receives the values of the geometric KEO of the sky and the geometric KEO of the facades of the opposing buildings (if any). Then the program calculates the coefficients by which the value of the geometric KEO is multiplied (and divided by the safety factor). The calculation of the coefficients is based on geometric parameters (for example, the size of the room, the dimensions of the opposing building, the distance to it) and the non-geometric properties of objects (the material of the facade of the opposing building, the microclimate of the room). When calculating the coefficients, various development schemes (the location of the opposing buildings) are taken into account.

After calculating the geometric KEO and coefficients, the program receives the calculated KEO value. Depending on the type of room and the orientation of the light openings on the sides of the horizon, the normalized value of KEO is calculated (according to SanPiN 2.2.1 / 2.1.1.1278-03, SNiP 23-05-95 *). The calculated and standardized values of KEO are compared, while the calculated value of KEO is allowed to decrease from the standardized value by no more than 10%.

For rooms containing several windows, KEO is calculated for each window separately, after which the results are summarized.

At the end of the calculation, the program determines the compliance with the standards for KEO rooms and apartments in accordance with the requirements of SanPiN 2.2.1 / 2.1.1.1278-03.

Insolation calculation results (reporting tables, windows insolation graphs, insolation angles, object shadows shading the edges of objects) can be viewed on the screen or output to a printed report (directly to a printer or to graphic files on disk). For library objects, it is possible to generate a detailed report in an MS Word file containing the results of calculations and substantiated conclusions about the implementation of insolation standards and KEO in rooms and apartments.