Peng Jie Teoh

Main Graph

• The main graph allows the input parameters to be changed, before they get sent into the main custom node that tests the various combinations based on the 2 input parameters that can be varied (height and twist of building are used in this case). The results are then exported to the Excel File. Additional nodes have been included, so that the input parameters that were varied can be automatically updated in the Excel File, instead of having to update them manually.
• Key changes since Module 5: Adding one more input parameter to vary and updating the exporting of the data onto the Excel File to reflect this additional input that was varied.

Main Custom Node (Building Form Evaluation)

• The Main Custom Node (Building Form Evaluation) from Module 5 was updated to include the new Evaluator Custom Nodes that were created for Module 6. The new Evaluator Custom Nodes were embedded in this Main Custom Node as it allows this node allows for the various combinations of the input parameters (height and twist in this case) to be tested and passed through the Evaluator Custom Nodes, before being sent out as outputs. New input nodes and output nodes were added accordingly, to meet the needs of the new Evaluator Custom Nodes.

Evaluator Node 1 - Floor to Area Ratio (New)

• The Floor to Area Ratio (FAR) evaluator node measures site utilization efficiency, indicating how much usable floor area is gained per unit of site footprint. The node also allows the developer to check if the designed building meets the local zoning regulation/allowable FAR.
• The FAR controls the size of buildings in relation to the size of the lot that they are built on. It essentially sets a limit on how much floor space a building can have relative to the lot area, which helps municipalities manage land use and prevent overdevelopment.
• To calculate the FAR, two values would have to be obtained - (i) the site area, which is fixed based on design brief (included as input under the Main Custom Node); and (ii) the total floor area for the entire building, which is extracted from the model that have been parametrically flexed. A code block has been added to do the calculation before the output gets fed back to the main custom node and main graph to be reported in the Excel File.

Evaluator Node 2 - Cost of Construction (Adapted)

• The Cost of Construction node allows the developer to get a rough sense of how much the construction of the building would cost, based on the input parameters (height and twist in this case) that were varied. This would allow them to be able to decide on the cost vs. design trade-offs to decide which is the best option to pursue.
• This Cost of Construction node largely follows the two custom nodes that were included in the examples, but they were re-built from scratch and it combines the two custom nodes into one, eliminating the intermediate steps and also the nodes/outputs which were not required for the purpose of this evaluation. This creates a cleaner node for the evaluation.
• A significant amount of time was spent on troubleshooting on the MassFloor.Mass node that was included in the example nodes, which we eventually realized was not required (after consulting the TAs), and finally got the entire custom node to work.
• The fixed parameters were provided based on the design brief - assume that the construction cost per square foot will grow linearly from USD $500 per square foot at ground level to USD $1000 per square foot at 750’ above the ground. The level-to-level height is also a fixed value, given that the design of the building has a standard 12’ floor to floor height. These fixed inputs were included in the Main Custom Node.

Evaluator Node 3 - Surface Area to Volume Ratio (New)

• The Surface Area to Volume Ratio (heat loss form factor) is a measure of how compact the building is. It represents the amount of building surface exposed to the outside relative to the volume enclosed by the building. A lower ratio indicates a more compact building, meaning less surface area from which heat can escape or gain. Ratio values like 0.05 – 0.1 are common for skyscrapers, especially those with slender profiles (tall towers) that are designed to optimize space within smaller footprint areas. This ratio allows the developer to make a more informed decision on the option to pursue, since they would have a better sense of the potential energy performance (heat loss/gain translates to heating/cooling requirement) of the building better.
• For the Surface Area to Volume Ratio node, the input is the building element generated by the Main Custom Node, and the Gross Surface Area and Gross Volume is extracted from the element for calculation. Given that the Surface Area required in the calculation also takes into account interior wall, an additional input has been included in the Main Graph, which is an integer slider on the Interior Wall Area (as a % of the Exterior Wall, for simplicity of calculation). This slider option would allow developers and designers on the amount of interior wall area (as a proportion to the Gross Surface Area) to pursue for their detailed design.

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 three evaluation metrics effectively capture meaningful differences between the building form alternatives. They provide a well-rounded view of spatial efficiency, cost, and thermal performance, enabling informed comparison of the design options.
• Floor Area Ratio (FAR) measures site utilization efficiency, indicating how much usable floor area is gained per unit of site footprint. Taller, more efficiently packed forms scored higher, making them more attractive for high-density urban contexts.
• Construction Cost, based on Gross Floor Area, quantifies the economic implications of each form. It shows how twisting or increasing floor area affects total cost, which is critical for comparing feasibility.
• Surface Area to Volume Ratio helps assess the form efficiency and potential thermal performance. It highlights how increasing height tends to reduce SAVR (more compact forms), while greater twist increases it (more surface area for a given volume).

What other metrics would be useful to compute to help understand and make the case for which alternatives are truly better than others?

• Daylight Access or Solar Exposure: Calculating facade surface orientation and solar gain can help identify forms that maximize passive lighting or minimize heat gain, critical for sustainability goals.
• Wind Load Exposure (Surface Area by Orientation): For tall towers, wind load impact varies with facade articulation and orientation, affecting structure and cladding design.
• View Quality or Orientation Distribution: Measuring outward-facing facade area toward favorable directions (e.g., city, sea, park views) could quantify marketable value.
• These metrics would provide a fuller picture across environmental, economic, and functional performance, enabling a more well-rounded recommendation.

Module 6 ACC Folder Link:

https://acc.autodesk.com/docs/files/projects/6db2c3ca-7a2c-4f34-96a1-8a8189c7754d?folderUrn=urn%3Aadsk.wipprod%3Afs.folder%3Aco.x1zQgp69QSCyPA8mcHnCUQ&viewModel=detail&moduleId=folders