New Custom Node 1: Average Insolation Custom Node
New Custom Node 2: Embodied Carbon and Cost of Slab Custom Node
Template Structure Table With Results
Custom Structure Table with Results
Stage 1 (2 units)
Important metrics that can drive owner decision-making include exposure to natural light, construction cost, and embodied carbon. I created two custom nodes that collectively capture all three of these.
Using the Dynamo Solar Analysis package, I developed a custom node that calculates the average insolation of a tower over a specified time period. The node takes in location-based weather data, time parameters, and the building massing as inputs. While the Solar Analysis package offers several output metrics, average insolation was selected as it provides a single, intuitive measure of overall solar exposure across the entire facade. For this analysis, a single representative day was used to demonstrate the workflow, though the node accepts any date range. For the analysis, I moved the two towers in my revit file far away from each other so they did not shade each other.
Assuming a concrete diaphragm structural system, slab embodied carbon and material cost become meaningful design considerations. The second custom node calculates both metrics based on the GFA of the tower. The node accepts a user-defined slab thickness to reflect different structural assumptions, and applies unit conversion multipliers internally to compute both the embodied carbon in kgCOâ‚‚e and the estimated concrete cost in dollars.
In addition to logging these metrics in Excel, the Dynamo code block was programmed to automatically flag the best-performing alternative for each metric, giving the owner a clear and immediate basis for comparing design alternatives.
In addition to recording these metrics in Excel, I was able to code in the code block the best options based on the metric (for extra credit). This gives the user/owner a very easy way to interpret the data from the model and can make the decision process of which alternative to go with much easier.
Point to ponder:
The three metrics captured (average insolation, slab cost, and embodied carbon) do reflect meaningful differences between alternatives, though their sensitivity to twist angle is minimal. Since GFA remains relatively constant across twist angles, slab cost and embodied carbon change only slightly between alternatives. Average insolation proves to be the most discriminating metric in this study, as the orientation and surface exposure of the facade shifts meaningfully with twist angle.
Additional metrics that would strengthen the analysis include facade surface area exposed to direct solar gain (relevant for glazing and HVAC loads), structural steel or core concrete volume (since a higher twist angle likely increases lateral system demands), and a wind exposure metric such as pedestrian-level wind speed. A more complete picture would also include a cost-per-square-foot metric that normalizes construction cost against rentable area, which is ultimately what a developer cares most about.