Architectural / exposure considerations for an angled lot?
oldbungalow
| Posted in Energy Efficiency and Durability on
Hi, considering building a SW/NE oriented home, approx. 39th parallel Zone 4. Not exactly N/S facing. 🙁
Any special EE considerations (windows, overhangs) that we should implement? Particularly if we want some passive solar benefits, or just want to reduce summer heat gain (cooling loads) in the mid-Atlantic?
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Replies
There are a lot of online calculators for doing shading:
https://www.insol.co.nz/overhang-annual-analysis-shading-calculators
You generally want to avoid too much solar gain in the shoulder season (Sept to Nov). You can get a fair bit of glare from south facing windows, you should look at where the light will fall in the winter and makes sure that it works with your interior layout.
Best of luck.
"You generally want to avoid too much solar gain in the shoulder season (Sept to Nov). You can get a fair bit of glare from south facing windows"
And then there are my current clients whose design brief included: "We want an insane amount of south facing windows!" Sigh...
Malcolm: Insane amount of south facing windows? That sounds like us. In our great room, we have a section of windows about eleven feet on a side facing south. Three foot overhang keeps summer mid day sun at bay. But on days like today, sunny, but cold (teens, 40 mph wind), all that solar gain is delightful. Plus the views are to the south.
Stephen,
Most of the view lots here overlooking the straits are south facing so the urge is to put as much glazing as they can on that side. One complication is our seismic requirements. This house will end up with a steel moment-frame, rather than the plywood shear-wall I'd prefer. Once again the structural engineer will make more off this job than I will.
thanks this this very helpful. part of me thinks the normal issue of Western wall summer afternoon solar gain is somewhat improved with a SW orientation, as the Western wall is now turned away, with only late-late summer afternoon sun making an impact. Conversely, the Southern exposure, now SW, get's a bit walloped.
With deep roof overhangs on the SW side and more modest overhangs on the SE side you can take the bigger gulp of solar gain in the morning when it's most needed/welcome in winter and least problematic in summer, since it's lowest temperature part of the daylight hours.
I say windows make lousy walls!
If you have a great view put in some windows and point your house that way.
When I did a BEopt model of my home I was shocked at how little difference orientation made.
The very best answer would come from your own modeling.
Walta
I have found that optimal control of solar gain requires external adjustable shading. It's simply not possible to get the shading you want with one setting, no matter how carefully calculated.
Check out this website on window coverings and attachments: https://windows.lbl.gov/software/aercalc. I know that LBNL is working on including external shading in the software but I am not sure how they can do adjustable external shading.
Peter