Building Form & Recommended Design
Building Form
Martini Glass Profile Twisting Form
Recommended Building Form
Results: Top Height 350 & Top Width 150
Node Logics
Main Dynamo Logic
Full Graph
Custom Node 1 - Construction Cost with Productivity Factor
Node: BuildingFormComputeCostByFloorArea_Prod(1) Main Graph
Zoom in on Productivity Logic
This node computes the total cost for the project based on a cost per square foot function. I tweaked the function a bit though to include a multiplier associated with the contractor productivity rate. This is based on the idea that in larger floor plate areas a contractor may gain productivity being able to do more things at larger scale (potentially more efficient concrete pours, layout is easier, etc). This would reflect in a potentially lower cost/sf and manifest itself on the contractor side as a discount rate. At a given critical area (e.g. 30,000 sf) and a discount rate (e.g. 5%), this node calculates each floor that is larger than the critical area and then, for each floor that satisfies this criteria, it multiplies the cost per sf (calculated similar to the examples) by the Productivity Multiplier (between 0 and 1) to given that discount for the floor. This is an attempt to refine the cost/sf function.
Custom Node 2 - PV Energy Cost Savings
Node: BuildingFormSolarAnalysis - Main Graph
Zoom in on Calculation
Single Optimization Scheme
Optimization Criteria
For my optimization, I wanted to look at mainly cost, but also take into account the solar PV potential (as more of a sustainability gesture/investment than an idea of generated a meaningful amount to offset a high rise total energy usage). That said, the three factors that play a role in the optimization area:
- Total Cost per SF (priority 1) - minimize
- This is important as many clients/developers have a range of Cost/SF that they can get approved by lenders since it relates to how much space they could rent out. This is why I put it as priority 1 (meaning it has the highest weighting factor of the 3).
- Total Cost (priority 2) - minimize
- overall project cost does matter, just potentially a bit less than Cost/SF.
- Total Annual Energy Savings from PV (priority 3) - maximize
- I wanted to take into account the PV generated onsite (related to the total surface area of the facade/roof).
To combine these I used the following weighting factors. I ultimately calculated the combined value by summing up the weighted totals.
Main Graph Logic - Single Object Optimization
Custom Node Logic - Single Object Optimization
Node: EvaluationResults_ComputeCombinedEvaluator
Since I wanted to minimize the cost elements and maximize the PV energy savings, I normalized the values as follows (zoomed in to the blue group noted above):
Summary Table & Results
Summary Table
Based on the results, it does seem that my optimization scheme heavily favors the lower height forms (which make sense since building higher costs more and usually is a higher overall cost per sf). That said, this now gives me a solution set (the green and yellow values) to dig more deeply into and find out what other optimization factors and components I might want to add to find the “best” case. See below for the recommended test cases and their forms. Test run #2 is considered the “Best” in this case because it has:
- the 2nd lowest cost per square foot
- the 3rd lowest total cost
- has a reasonable rank of annual PV generation energy cost savings.
Note that this scenario does not have the lowest cost per square foot, the lowest total cost, or the highest energy savings from PV generation. This is a truly an “optimal” case in this regard.
Top 3 (really 4) Recommended Test Cases
1st Place (run #2)
Results: Top Height 350 & Top Width 150
2nd Place
Results: Top Height 350 & Top Width 200
3rd Place
Results: Top Height 350 & Top Width 100
4th Place
Results: Top Height 450 & Top Width 150
