Sun chart for new build

grumps

I'm currently looking to draw up a sun chart for a new house, in order to assess the degree of shading on the building facades due to terrain features, local landscape features and surrounding buildings etc.

Anyone have any expericence of graphically sketching these. Have been on the University of Oregon site, from where I downloaded the chart appropriate for my latitude/longtitude. But can't seem to find much guidance as to how to actually complete the chart.

any advice would be great.

CJhaughey

Google sketchup has a sun feature built in, have you looked at it?

sydthebeat

i agree with CJ.

sketchup is extremly easy to use to draw up your buildings in 3D. then either import into ggogle eart or input location manually. Then generate sun and shadow diagrams from this.

either that or purchase 'BRE Digest 209: Site Layout Planning for Daylight and Sunlight'... costs about €70 for pdf download

The Obvious

http://mathworld.wolfram.com/CylindricalProjection.html

Basically, what you need to do is draw all the obstacles in the chart you already got. Actually it is pretty simple.

For each obstacle do the following:

1. Measure obstalce azimuth, for example an obstacle SE from your point of view will have 135° azimuth. I do this in AutoCAD measuring angle from a north direction, you can do this on any map.
2. Mark the azimuth on your chart.
3. Calculate the obstacle's elavation, bit of math here...

elevation = atan ( obstacle's height / distance to obstacle )

don't forget to use same units for height and distance (meters, feets). Since I do this calculation for 10-20 obstacles, I use an EXCEL spreadsheet... up to you.
4. Mark the obstacle's elevation above the already marked azimuth. If the sun is "above" the obstacle, it shines on you.


For more complicated obstacles, you'll have to plot few points and connect them on the diagram to approximate the object's outline.


Yea, that's the best I could do in writing... hope it helps )

grumps

thanks all.

came across a useful enough webpage at

http://www.builditsolar.com/SiteSurvey/site_survey.htm

which helps you evaluate your site using the sun chart method.

I'll try and give SketchUp a try too if I get a chance.