should the below grade portion of the building wall be included in the wall area for purposes of calculating window to wall ratio in BeOpt?

asked 2019-09-02 20:34:43 -0600

skrucial
31 ●4

updated 2020-01-07 19:57:48 -0600

__AmirRoth__

4436 ●5 ●17 http://bleedinggreenna...

When modeling a single family residence, and when the basement is included in the conditioned space, how should i define the wall area? With or without the below grade portion? Further, Does beopt provide an option to include the ration of the basement walls that are above/below grade?

answered 2019-09-03 12:08:33 -0600

shorowit

11811 ●200 ●9 https://www.nrel.gov/b...

The wall area, for purposes of window-to-wall ratios, does not include the below-grade wall area. You can confirm this by drawing a building with a slab foundation type, looking at the absolute "Total Window Area [sqft]" that BEopt calculates for a given Window Areas option, and then changing the foundation type to a conditioned basement. Note that the absolute window area is unchanged.

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That said, if you have a specific window area you're trying to achieve, you can create a Window Areas option where you specify absolute areas instead of window-to-wall ratios. See the "50sqft, all facades" option as an example of an option with absolute window areas that are unaffected by the drawn building geometry.