Changes from Module 5:
In the Module 5, three single input parameters (Base Radius, Top Height, Top Rotation) were varied one-by-one while keeping other inputs constant. In Module 6, this was changed so that two input parameters (Base Radius, Top Height) were varied by each possible combination, while others remained constant. Additional evaluation metrics (EmbodiedCarbonTotal.dyf, Panels.ComputeDirectnessToObject.dyf) were included in this main node logic, such that sub-custom nodes were embedded into the main custom node (BuildingForm.EvaluatePairsOfInputs.dyf) that adjusts the varied input parameters.
Note: Green block is the new, added node logic into the custom node
Evaluation Metric 1: Embodied Carbon Based on Floor Mass Areas
EmbodiedCarbonTotal.dyf was modified based on the custom node Glenn provided from his example, where the Floor Areas were extracted. Using these areas, total embodied carbon was calculated in the building, where the first 10 floors are concrete (46.45 kg/ft^2) while the rest of the floors are steel (32.53 kg/ft^2) to represent podium construction. Embodied carbon was calculated by multiplying the floor area to its corresponding factors. To generate values for each testing case, this custom node was embedded in the main custom node BuildingForm.EvaluatePairsOfInputs.dyf.
Evaluation Metric 2: View Quality of Top 10 Floors Based on Directionality of Panels Per Floor
Panels.ComputeDirectnessToObject.dyf was modified from the custom node provided by Glenn. The blue code groups are the original code, where panel normals and centerpoints are computed and related to vectors from the reference object. Note that the reference point provided by Glenn was adjusted so that it takes into account of a reference object using Element.GetLocation. The directness scores of each panel is computed, from which a total sum can be attained. Additionally, the view quality of the top 10 floors was evaluated. This includes the average directness score, the percent of panels with a score of at least 0.75, and the location of the best aligned panel (via GetItemAtIndex). These were computed by calculating a cutoff threshold that is used to filter only the top 10 floors depending on the height of the tower through a Boolean mask. The directness scores of the top 10 floors are obtained to calculate the new evaluation metrics.
To generate values for each testing case, this custom node was embedded in the main custom node BuildingForm.EvaluatePairsOfInputs.dyf.
Summary Table:
Points to Ponder:
Do the new evaluation metrics that you’ve designed capture the meaningful differences between the building form alternatives?
- Yes, the additional evaluation metrics allow us to capture differences between the building form alternatives that could optimize material efficiency, sustainable construction, and comfort during occupancy. It allows for a quick and insightful comparison for engineers to decide on the most optimal form.
- Total Embodied Carbon measures the total greenhouse gas emissions (typically in kg CO₂e) associated with the materials used in the building. Embodied carbon accounts for about 40–50% of a building’s total lifecycle emissions before occupancy, thus it can help evaluate the sustainability of the material choices and carbon trade-offs between form, height, or taper. Factors may be adjusted to try new materials in this custom node, and to change which floors a material applied to.
For top 10 floors:
- Average Directness Score measures how well the top-floor panels face a view target. If this is a luxury apartment building, for example, it is important for the building owner to prioritize the comfort of their occupants. This includes the overall view orientation (sun, ocean, landmark, etc).
- Percent of Panels with a Score e ≥ 0.75: This measures how many panels are strongly aligned with the view. This can help building owners gage real estate prices based on how many premium units offer good views.
- Location of Best-Aligned Panels: This tells which panel is most ideally oriented toward the target, such that designers can place high-value functions in the direction of these panels (i.e. balconies, suites, terraces, curtain walls).
What other metrics would be useful to compute to help understand and make the case for which alternatives are truly better than others?
- Solar Exposure: Calculating the solar exposure and how much natural lighting into certain facade surface orientations allows designers to identify optimal building forms and orientations that maximize passive lighting or minimize heat gain. This can help reduce the amount of artificial lighting installed in the building, increasing sustainability.
- Surface-Area to Volume Ratio: A lower ratio means that the building is more energy efficient, such that there is less envelope exposure per volume.
- Corner Units Count: Higher value (real-estate) units are typically corner units in a building, where there is more exposure and daylight, as well as a larger view area.
- Wind Load Exposure: By calculating the surface area by orientation, facade detailing and orientation may be adjusted to ensure that the tall building is structurally stable against wind lateral loads. This could affect cladding design and the overall form of the building depending on the wind exposure in the particular building site location.