For this module I used the same building geometry as in Module 5 with the objective of not only creating different alternative designs, but also assess them against each other and evaluate which would be the best design based on my ranked criteria. Overall, I evaluated two new metrics and incorporated all of the analysis into a single custom node. The two metrics are Cost to Build and Line of Sight (score). Below is a snapshot of my overarching custom node and the discussion below explains the logic sequence.
New Evaluator Nodes
Cost To Build
Cost is an important factor in any construction project so I thought it would be appropriate to include cost to build as an evaluation metric. To do this, I assumed that the cost to build a unit of floor area would increase linearly from $700/sqft at ground level to $1,500/sqft at the top level of the building (floor 62). I then pulled out the mass floor elements from my building form and for each mass floor, identified what building level it corresponded to. I then created a list containing the amount of floor area at each building level and multiplied it the corresponding cost to build per square foot at that level. As a starting point I used the BuildingForm.MassFloors and the BuildingForm.EstimateCostByFloorLevel custom nodes and modified these to 1) reflect the distribution appropriate for my building, and 2) to adapt to my overarching custom node.
Line of Sight
Real estate becomes significantly more valuable if it provides nice views to the tenants so for this reason, I decided to include a score for line of sight as an evaluation metric in my design. While not wholistic in the analysis to confirm beautiful views, this evaluator serves as a proxy to identify parts of the building that enjoy unobstructed views. To do this, I took my building envelope surface and panelized it. Then for each panel, I located the center point and created a short line in the direction normal to the surface. To correct for any vectors that ended up pointing toward the interior of the building I intersected the lines with my building volume (solid) and reversed any lines that intersected. The result was a 2,000 ft-long vector jetting out from each panel on my building exterior. Then, I created three “dummy” buildings in the vicinity of my building and evaluated if any of the vectors crashed into them. Finally, I calculated a Line of Sight score as the percentage of total vectors that had unobstructed views (i.e. that did not crash with nearby buildings).
Evaluation and Recommended Design
Overview of main Dynamo graph:
Overview of overarching custom node:
In evaluating which building design was the best, the first criteria used was to ensure that the total floor area was within the range specified in the design brief (1,200,000 sqft - 1,500,000 sqft). Designs that did not meet this criteria were disqualified. Then, a weighted score was given to each of the remaining designs. This weighted score prioritized the following three criteria (listed in order of decreasing importance):
Cost to Build (the lower the cost the better)
Line of Sight score (the higher the score the better)
Gross Surface Area (the lower the surface area the better)
By exporting the results of this evaluation to excel, it became evident which design was the better to recommend for the client. The recommended design has a Base Radius of 125ft, a Mid rotation of 30 degrees, and a Top Heigh of 750ft.