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I want to buy a house and I'm asking myself what quantity of daylight the various sides of the house receive.

I know the house is roughly oriented in the east-west direction.

But I'd like to know the exact apparent path of the Sun around the house depending on seasons, with (ideally) the elevation angle of the Sun.

Is there a technical term for "the apparent path of the sun at a given point of the Earth, at a given time of the year"?

Also, is there an online tool that allows one to visualize this path on a map?

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    $\begingroup$ Unless you're comparing houses that are very, very far apart, the main difference in sunlight is going to have to do more with the local topography. One hill or tree in the right place can make a huge difference. $\endgroup$
    – user3067860
    Mar 6, 2021 at 22:36
  • $\begingroup$ "sunward"; cf. deasil $\endgroup$
    – Luke Sawczak
    Mar 7, 2021 at 22:54

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Merriam-Webster defines diurnal arc:

the portion of the diurnal circle of a celestial body that is above the observer's horizon

and diurnal circle:

the apparent circle or parallel of declination described by a celestial body in consequence of the earth's rotation

The NOAA Solar Calculator does not implement the exact feature in question but can show the Sun's azimuth for any given location, date, and time.

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The apparent path of the Sun in the sky is called just that, 'apparent path of the sun'. Sure enough it varies with location and with time-of-year, especially the further you live from the equator. The Sun will rise and set exactly East and West on the equinoxes, and be highest in the sky at noon in Summer on mid-summer (21th June or 21st December) and lowest at noon at winter solistice. Between rise and set for any day you can approximate the apparent path's height (or zenith angle) quite well with a parabola (a sine curve is better).

The photographer's ephemeris is a nice tool which visualizes the Sun's and Moon's path for any chosen location and date and which can also take into account the topography. Registration is free.

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Dynamic daylighting

Dynamic Daylighting is an impressive, free, online tool written by Andrew Marsh.

This app investigates real-time dynamic daylight analysis within a simple rectangular room based on detailed sky distributions. The room size, windows, external shading devices and work plane height can all be interactively manipulated with the internal daylight distribution updating in real time. You can add any number of windows, external shading devices or site obstructions, and experiment with different surface reflectances and window transmittances.

You can specify the location of the building, resize it, rotate it and add external buildings.

screenshot

You can also download weather data, import it and launch a simulation for a whole year, which outputs hours of sun per year.

Other tools

You might also be interested in other apps written by Andrew, e.g.:

and more in accordance with AstronomyStackExchange:

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"Path of the sun" would seem to be a sufficient term.

The SunCalc app can give you want you need. It can tell you the position of the sun in the sky at any time and on any date So it can tell you that on March the 6th in Lyons KS, the sun rises at 6:56, on a bearing of 096 (about 4 degrees south of east) reaches a maximum height at 12:43, when it is due south and an elevation angle of 46 degrees above the horizon, and sets at 18:31.

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