Calculate shadow area

[b.yu563AN]

Hi all,

Is there anyone who know how to calculate the area of a shadow cast onto the ground floor by a buiding, or know of any dynamo tutorials. Its for several buildings onto a large site.

I've searched all over and Revit does not seem to support this. Is there other programs in which i can import my revit model to calculate shadow casted for me? 

[constantin.stroescu]

as long as Shadows in Revit are raster images not vectors, I don't see how we can grab them and make measures...

The only way I see is to draw Filled Regions over the shadows (no snaps of course) and then to obtain the area from them...probably by using Dynamo (as shown bellow)

[mhiserZFHXS]

There are so many factors involved with this. Is there a certain time you want the shadow to be calculated? (9AM, Noon, 5PM?) Where is the building located? What time of year is it? What if a portion of the shadow doesn't actually reach the ground, and hits another building? What if the site isn't level?

If you just want the roughest estimate (how much area WOULD this building's shadow cover, assuming the site is flat, and no buildings/trees/etc interfere with the shadow), you could use algebra and trig to use the sun's altitude and azimuth along with the geometry of the building. But of course this would only provide the shadows for the date and time you use to find the angle and azimuth.

[ToanDN]

Create an area scheme for each calculation and trace the shadow with Area separation lines, place Area(s), then tag/schedule them.

[RDAOU]

@b.yu563AN 

Check the YouTube channel of Aussie BIM Guru  https://www.youtube.com/c/AussieBIMGuru/featured

He had a 4 or 5 parts tutorial on how to generate Shadows diagrams using dynamo

[idoYKZAL]

Check out Shadow Colour for Revit it includes area calculation 

[stefan_gokstorp]

its math actully if you have the real world location which time of day (suns zenith at that geographic location) and the height of the building.

its just down to trigeometri 

formula is  L=H/tan(a)

L is shadow lenght
H is height of you object
a = the angle of the sun

see link below for calculator
https://calculator.academy/shadow-length-calculator/

for using in revit i think the easiest way would be to use a parameter controlled by the forumla mentioned
but note depending on which time of day direction(angle) of the sun will be diffrent for diffrent houses so first task would to figure out the suns angle in correlation the the diffrent houses and after that do the calcualtions.

[lucdoucet_msdl]

@b.yu563AN 

The Autodesk University class below has a description of a Dynamo script and Video link which calculates the area of shadows cast by a building on a level. Unfortunately, the script doesn't seem to be attached and the screen capture doesn't show the node names. It maybe readable in the Presentation slides download.

Solar Analysis: Calculating Shaded Areas in Revit for Sustainable Design

Haven't tried this but, hope it helps.

-luc

[idoEJKK3]

Check out the plugin 'Shadow Colour' for Revit