As we find in the text above, the quantitative part of the solar radiation can be efficiently analysed with ratios of building shadows influencing the surroundings and vice versa. This relation influences:

• building geometry,

• distances between buildings,

• orientation,

• duration of solar radiation

• during the chosen period of

• time,

• layout density

• consequently number of

• residents on site.

Solar rights in Slovenia

In 1988 the Sanitary Inspectorate of the Republic of Slovenia issued an obligatory instruction on minimum sanitary and technical parameters, which have to be considered when assessing the physical planning acts. One of them is minimum duration of solar exposure of living spaces during four reference days in a year that has to reach at least 1 hour on the 21st of December, 3 hours on the 21st of March and the 21st of September and 5 hours on the 21st of June.

Simulation model

The simulations were carried out for a flat site in Ljubljana (latitude 46.03 N).

As a reference a building with the following geometry was simulated:

• length (L) 60 m,

• width (W) 12 m,

• height (H) 6 m (2 floors),

• longer facades facing S and N.

For each type a site layout, consisting of four parallelly positioned buildings was designed. The required site size for four buildings was measured according to shadow contours delineated with boundary lines, marking a rectangular site.