As the developer, we care the cost and the quality of our product. To deliver a high quality while cost effective building, the two new metrics considered are “Cost per Floor Area ($/SF)” and “Directness to the Bay Bridge.
The new form still wants to maximize the base radius, with a limit of 300’/2 = 150’. It has larger medium radius and lower height.
Custom Node 1: Cost per Floor Area
With a complicated building shape changing all 3 radius on the base, medium, and top, it could be quite hard to know which design has the overall lowest unit cost. Thus, as a developer, the average unit cost per floor area an important factor to consider.
- In 4A, we first extract the floor area on each level.
- Based on linear interpolation, we calculate the construction cost of each floor and sum them up to get the total construction cost of the building.
- Use the total cost of the building dividing the gross floor area, we get the unit construction cost per floor area.
Custom Node 2: Directness to the Bay Bridge
The view to the Bay Bridge is a key factor for the quality of the building. Thus, a larger directness to the Bay Bridge indicates better view and higher quality.
- The surface are created based on the input of number of UV panels, and direction vectors are calculated.
- Based on the input of the latitude and longitude of the project and the Bay Bridge, we can get a vector. In this case, we assumed the altitude to be 0 for both locations. The project location is (37.7896, -122.3931, 0) and Bay Bridge location is (37.7990, -122.3776, 0). The vector from project to Bay Bridge is (0.519, 0.855, 0).
- Compute the dot product between each panel and the direction vector to Bay Bridge, and then sum each one of them up. The number of the panels would also affect the directness. In this case, a larger number of panels results in larger directness value.
Part 2: Design a Single-Objective Optimization Scheme
There are 5 values being evaluated. Two are the metrics in part 1, the cost efficiency and the directness to Bay Bridge. The other three are insulation performance, shape efficiency and space efficiency. Shape efficiency is floor area divided by surface area, the higher the more efficient. The space efficiency is the floor area divided by gross volume, the higher the more efficient as well.
The weight of the cost efficiency and the space efficiency are set to 2, and others are 1. The weights are assumed with more important factors a higher weight. While we do not know what the real weight is.
The highest score design is the lowest height and largest twisting angle. A lower building means a smaller gross floor area and a lower construction cost, which is valued. A higher twist angle also results in better view to the Bay Bridge and lower insulation value. Thus, it is gains the highest point, together with high space and shape efficiency.
Evaluate Custom Node:
The larger $/SF, the lower the cost efficiency is. Thus, there is a negative sign in front of score 1. All other factors are the larger the better. Thus, there is a interact and tradeoff, that higher building could have better space efficiency while the cost efficiency goes against it.
Step 5: Create a Simple Revit or Rhino Model
First, the wall surfaces were selected, and panels were added on the 3 surfaces. The “Rect_Panel with Resizable Opening: Glazing” was chosen.
Step 6: Provide Visual Feedback By Adjusting the Appearance of the Panels
Refer to the example, I used the custom nodes in it. Red corresponds to more sunlight and thus smaller panel opening and vice versa.
Custom Node: Panels.ColorizeBlueToRedValue