EUI - orientation/shading/overhangs

[karim_daw]

I am wondering whether someone could indicate to me what exactly is affecting the EUI of the buidling.
I have looked at these two links:
https://help.autodeskforma.com/en/articles/8480701-rapid-energy-analysis-technical-documentation#h_4...
https://help.autodeskforma.com/en/articles/7053939-introduction-to-rapid-energy-analysis

While i understand that the parameters you have indicated, being the construction, compactness, galzing etc. Is there somethign in the model that takes into account the orientation of the building?

[larry.schirmer]

The rapid energy analysis passes a number of inputs to the energy model. The parameters you mentioned from the article are direct inputs for this model. We also process the geometry from the forma scene into derived features that the model uses to approximate the final result. For each building (or group of buildings if they share a wall or roof), we calculate the orientation, envelope area, roof and floor area, and the building's max height. These derived features and the settings specified in the right menu are passed to the model to generate an approximate EUI for each building. 

As for shading and overhangs though, we are looking to provide a more detailed energy analysis in the future which is able to take more detail of a building and it's surroundings into account. Today, the model is not able to process these factors. 

If you have anymore questions, I'd love to help.

[karim_daw]

So for my understanding. If you have a rectangular building in forma, the facade orientations are labeled and then used in the ML model? I did not see the explicit orientation labels in the feature list being inputted into the model. Can you confirm whether this is/is not the case

Also this model seems to be only trained on Residential projects correct?

[larry.schirmer]

That's correct. I'll bring this up with the team and see if we can update the documentation to include these details that we pass to the model about the buildings being analyzed. The model takes as input a measure of what percentage of the facade area is facing each direction. And it's also important to point out, as you said, that the current model is trained on the energy usage of multi-unit residential buildings. 

[karim_daw]

Understood. I conducted a test by building a building in Forma and calcualting the EUI. When i rotate it 90 degrees, there is no change to the EUI though..

[larry.schirmer]

I created a generic volume building with 1 floor where the width/height/length are the same and adjusted the settings to the most energy intensive category. The location and elevation of the building along with the other factors mentioned before will make this specific case unique. Just to isolate orientation though, I found rotating this building 45 degrees had a small effect on the estimated energy usage. At 90 degrees, the result was similar to 0 degrees.