For 2 or More Units: Create Two New Evaluator Nodes
- Images showing the node logic in your new evaluator nodes - Partial Shown Below
For the first evaluator nodes, I analyzed the ratio of exterior surface area to floor volume at each level. The surface area to volume ratio can be a great indicator for energy efficiency, where smaller ratio suggesting a better energy efficiency. I computed this ratio in two ways: the first way is by dividing the total exterior surface area (only the side surface) to the total volume of the building; the second way is to find the ratio of the two at each level and find the average of all the ratio. The ratio calculated from the average ratio is slightly higher than the other and I think it’s a better reflection of the surface area to volume ratio for the whole building. Additional to the results for the ratio, the sum of floor area, volume, and surface area can also be reported.
The second evaluator node is about the construction cost associated with exterior surface area (again only the side surface) and floor area. The construction cost is assumed to grow linearly as the height of the building increases for both area construction calculation, and the sum of each cost can be reported as well as the total cost. For this evaluation, I also reported the ratio of the cost for floor area and surface area for comparison. If look at the whole list, it can be seem that the ratio is larger with larger surface area, which could be a consideration when designing the building form, but the list is too long to report.
The Custom Node above combines the two evaluator nodes for loop testing.
- An Image/screenshot of your summary table (created in Word, Excel, Google Sheets, or any data table tool) showing the input values tested and the values computed for each of the reported parameters
Two parameters were tested, which are top rotation and mid rotation. The results of the two evaluators show a similar pattern: decrease first and then increase as the rotation angles change, meaning there is a minimum exist for both construction cost and energy efficiency. Based on the table, the min for construction cost is found at mid rotation of 15 and top rotation of 180 and the min for SA/V ratio is found at mid rotation is 30 and top rotation is 90.
- Your answers to the Points to Ponder questions for each stage of the assignment that you completed.
Do the new evaluation metrics that you’ve designed capture the meaningful differences between the building form alternatives?
For the cost evaluation metric, the separate cost output can be reflect the amount of usable space and the material usage, the combined cost can provide a comprehensive view of the building’s cost efficiency. The surface area to floor area cost ratio as well as the surface area to volume ratio can reflect balance between construction costs and space utilization and the energy efficiency of the building, which can then reflect the trade off between the cost and sustainability.
What other metrics would be useful to compute to help understand and make the case for which alternatives are truly better than others?
Even though the ratios can reflect the overall energy efficiency, they don’t provide exact performance figures. Thus, there are other energy performance and environmental impact metrics can be added to the evaluation, such as annual energy consumption, embodied carbon, and etc. Also, I think it can be helpful to look at the metric outputs for each level. As the floor and surface areas and volume are constantly changing, looking at each level output can bring a better understanding of the relationship of the outputs and those parameters.