For Module 5, I created my structure in Revit. I was having a lot of trouble with the program crashing, and was generally finding it difficult to understand the logic of Revit’s conceptual mass framework. This week, I decided to start from scratch and rebuild the model using Grasshopper in Rhino so that I could have more control over my design choices and get a better understanding of the looping logic.
My design is quite simple and consists of two ellipses of different sizes and rotations (the ground floor and roof, respectively) lofted together. The two parameters I chose to vary this week were:
- Size reduction factor between bottom floor and top floor (i.e. how much small is the roof than the ground, while still retaining the same elliptical aspect ratio).
- The angle of rotation of the building.
Since I was evaluating environmental responses of the building, I felt that these two inputs would give interesting results, especially since the structure’s axial rotation/direction will directly impact how much of its surface area is facing the sun. Last week I had tested height as one of the inputs — this is a crucial parameter, but I felt that I wouldn’t be getting much insight from a parametric test of heights that I couldn’t get from simple scaling of outputs. The two inputs I chose are a bit more nuanced and harder to extrapolate the effects without doing a parametric analysis.
I also created two new evaluator logics. The two metrics I evaluated were:
- Total construction cost based off the equation given in the assignment description
- Total solar radiation potential of the building in kWh/m^2.
Construction cost is a critical design element, and since we were given an equation for estimating costs in this region, I decided to implement that as an evaluator node by extracting the centroids of each floor and doing a linear interpolation function along the height of each centroid to calculate total construction cost.
I chose the solar radiation potential because it’s an excellent indicator of approximately how much energy a building can expect to collect from solar power, which is particularly important in a sunny area like Dubai, and in an advanced construction project that would try to take advantage of new, renewable energies. I took advantage of Grasshopper’s Ladybug plugin to calculate the yearly solar radiation potential based off a EPW map file I downloaded from https://www.ladybug.tools/epwmap/.
The screenshot below shows results from my parametric evaluation exported in Excel.
Point to Ponder: Do the new evaluation metrics that you’ve designed capture the meaningful differences between the building form alternatives?
Both the metrics I’ve designed are relatively crude approximations of nuanced construction metrics. However, they provide a good baseline for comparing building form alternatives. Some other key metrics would involve a daylight study, size of shadows cast by the building, costs associated with heating/cooling depending on the orientation, and more.