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Insolation & shading calculator
City
Window azimuth: 180°
Room type
Sill height above ground [m]
Wall thickness [m]
Obstacles (1/4)
Drag the building on the plan or type its distance from the window, offset and dimensions.Name
Distance from window [m]
Lateral offset (R+/L−) [m]
Width [m]
Depth [m]
H [m]
Insolation (TR §60)
21 March — 10 h 00 min
21 September — 10 h 00 min
Shading (TR §13)
Budynek 1: D = 14.4 m / required ≥ 10 m
Online insolation and shading calculator
The calculator checks whether a room meets the required direct sunlight duration on equinox days under §60 of the Polish Technical Conditions, and verifies window shading within a horizontal 60° cone under §13. On an interactive top-down plan you place neighbouring buildings, and the tool computes the hours of direct sun live and draws the shadow for the selected hour. You can freely drag the buildings on the plan or type their exact position along the X and Y axes together with their dimensions.
It is a tool for architects at the concept and building-permit stage — it lets you quickly assess whether the layout and window orientation will provide the required insolation before you fix the massing and the building position on the plot.
How to check insolation in 3 steps
Pick the location (city) and set the window azimuth — the direction the window faces. The calculator computes insolation immediately for both equinox days — 21 March and 21 September.
Choose the room type (residential room, studio flat, or nursery/kindergarten hall — for children, the window hours are 8:00–16:00) and tick downtown development if applicable. Enter the sill height above ground and the wall thickness.
Add obstacles and drag them with the mouse on the plan to the positions of neighbouring buildings — or type their X and Y position and dimensions. Read the §60 verdict on the timeline and the §13 shading assessment.
What the calculator computes
The tool performs a full set of insolation and shading analyses:
- Insolation time §60 — the total minutes of direct sun reaching the window separately for 21 March and 21 September (per court judgment, the requirement must be met on both days), between 7:00 and 17:00 for residential rooms and 8:00 and 16:00 for nurseries/kindergartens, compared with the 3 h threshold or 1.5 h in downtown development.
- Shadow simulation — the shadow cast by neighbouring buildings onto the ground plane for any hour, controlled by the time slider.
- Shading §13 — a check that within the horizontal 60° cone from the window axis no object stands closer than its height (D ≥ H; 35 m for taller objects; 0.5·H in downtown development).
- Accurate sun position — with declination, the equation of time and corrections for longitude and time zone (winter time on 21 March, summer time on 21 September).
Important design notes
The result is auxiliary and does not replace a full insolation analysis in the project documentation. The model assumes flat terrain and cuboid obstacles; one window is analysed at a time. Self-shading by the building’s own balconies and loggias is not included. In downtown development, the threshold is 1.5 h, and for studio flats in such development insolation time is not specified — confirm the downtown boundaries against the local plan.
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