Topography in energy model

Rachel Williams

LEED Reviewer

USGBC/GBCI

LEEDuser Basic Member

0 thumbs up

August 19, 2022

Related to some recent questions on site-specific sun/wind analysis and early energy modeling tools, are there any tools that account for nearby topography (like bluffs) or large buildings/vegetation in energy calculations? Or favorite methods to estimate its impact particularly during early massing studies?

Thanks,

Rachel

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Daniel Stine

Director of Design Technology

Lake|Flato Architects

LEEDuser Basic Member

0 thumbs up

Mon, 08/22/2022 - 16:29

I think it depends on the tool used for early energy modeling. In our workflow, using Revit + Insight, it is possible to add mass elements to represent adjacent buildings. Masses can also approximate trees and bluffs if positioned correctly. This does not take into account seasonal variations in vegetation. All of these elements become 'shade surfaces' when sent to DOE2 or EnergyPlus. A related challenge is a sloped grade at a building's perimeter. Since the energy analysis model (EAM) creation is automated in our workflow, we have to split the difference when defining grade as a flat plane (below which, elements are defined at 'below grade' walls, floors, etc. in the energy modeling engine).

Kjell Anderson

Director of Sustainable Design

LMN Architects

LEEDuser Basic Member

4 thumbs up

Mon, 08/22/2022 - 22:45

The simplest example is a fisheye lens looking upward from the building – it will show the highest obstruction in all directions and can show the actual sunrise/sunset times for a site. The projection could then be used to create geometry in a model using a few simple faces. This was the first image on google that shows this concept. http://mendocinoarchitect.com/Solar%20site%20analysis.html F