# Calculate percent shading on surface **URL:** \ **Category:** Pro\ **Created:** [January 15, 2019, 12:51am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429 "2019-01-15T00:51:19Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Casey2U](https://avatars.discourse-cdn.com/v4/letter/c/b38774/32.png) [@Casey2U](https://forums.sketchup.com/u/Casey2U)\ **Post date:** [January 15, 2019, 12:51am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/1 "2019-01-15T00:51:19Z")
I need to figure out how to calculate shading % on a surface. I figure I can sort of do it manually by setting Parallel Projection with a view perpendicular to the surface(s), and then… counting? ugh. Oh, the surfaces might be a bunch of co-planar but separated surfaces (think: solar modules), so it would be nice if either it were fast & easy per surface (lots of repetition), or could be done on a bunch of surfaces at once. Assuming there is some clever way to do this. Let me know if that’s not clear. Thank you. ---
**Author:** ![Casey2U](https://avatars.discourse-cdn.com/v4/letter/c/b38774/32.png) [@Casey2U](https://forums.sketchup.com/u/Casey2U)\ **Post date:** [January 15, 2019, 1:52am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/2 "2019-01-15T01:52:18Z")
BTW, if there is no ready way to do this, I might be interested in building a plug-in to do so: is that likely to be possible? Any similar plug-ins I might be able to steal from, design-wise? Do people do that? ---
**Author:** ![sjdorst](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/sjdorst/32/13212_2.png) [@sjdorst](https://forums.sketchup.com/u/sjdorst)\ **Post date:** [January 15, 2019, 3:01am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/3 "2019-01-15T03:01:21Z")
[Sefaira](https://sefaira.com/) is another Trimble product aimed at energy analysis of buildings. They convinced our Moderators to open their own category here on this forum: [https://forums.sketchup.com/c/sefaira](https://forums.sketchup.com/c/sefaira) There are a couple of subcategories, including one for their Sketchup plugin. I’ve not looked into it beyond a bit of browsing on their website (linked above) for a few minutes when the forum category first appeared, but it seems to me they MIGHT have a solution for you. Not directly in Sketchup, but they have a plugin that connects (I assume) to their cloud platform and might have the sort of analysis you need. ---
**Author:** ![DanRathbun](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/danrathbun/32/500_2.png) [@DanRathbun](https://forums.sketchup.com/u/DanRathbun)\ **Post date:** [January 15, 2019, 4:19am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/4 "2019-01-15T04:19:40Z")
Also check the Extension Warehouse for other shadow study extensions. ---
**Author:** ![eric-s](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/eric-s/32/55392_2.png) [@eric-s](https://forums.sketchup.com/u/eric-s)\ **Post date:** [January 15, 2019, 4:57am UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/5 "2019-01-15T04:57:34Z")
I’ve used this one with some success: [Extension | SketchUp Extension Warehouse](https://extensions.sketchup.com/en/content/shadedat) Lets you hover over a given part of the model and tells you how many average hours of daylight a spot gets on a given day. ![July](https://global.discourse-cdn.com/sketchup/original/3X/4/0/40362f58c6c69d1f450f043ff535f04eb521a895.jpeg) ---
**Author:** ![janiaktomasz](https://sea2.discourse-cdn.com/sketchup/user_avatar/forums.sketchup.com/janiaktomasz/32/63001_2.png) [@janiaktomasz](https://forums.sketchup.com/u/janiaktomasz)\ **Post date:** [January 30, 2019, 2:02pm UTC](https://forums.sketchup.com/t/calculate-percent-shading-on-surface/85429/6 "2019-01-30T14:02:17Z")
We have a version of [Shadow Analysis plugin](https://deltacodes.eu/en) which does calculate shading %. It is not published yet, but if you would like to have a look at it please email me at office@deltacodes.pl and you can join our beta testers.