Question-and-Answer Resource for the Building Energy Modeling Community
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Adding to Greg's good advice here... Overhangs are most effective on south-facing walls because the sun is high there. Modeling overhangs on N/E/W orientations will likely have minimal effect on energy use and code compliance. Side fins can be more effective on the E/W orientations, as well as South. So use that filter before deciding whether it's worth the time to enter the overhangs. Realize too that if you comply without overhangs, it's better not to define them in the compliance model and add to complexity for review and inspections in the field. Also, if you're in a climate zone in CA (1,3,5, 16 and a few others depending on the design) that benefits from heat gain through windows, shading them may be detrimental to your model's compliance score. Also , the depth of the overhangs is important to get right -- enough to reduce summer heat gain but not too much to prevent winter heat gain, which is helpful. I have a blog post on my website on passive solar shading design that might be helpful in determining optimal overhang depth here: https://www.buildsmartgroup.com/net-zero-blog (about half way down).
