2 Units
The selected geometry is as follows:
This was selected out of the following possible combinations
In this case, the Base and Top dimensions were fixed. Height and Twist were varied to obtain multiple floor area, surface area and volume combinations. The Surface Area / Volume Ratio was calculated in order to see how efficient every design is. This ratio is commonly used for heat efficiency of buildings. In addition, the initial cost was calculated by modifying the BuildingForm.EvaluateValueByFloorAreaForTwoInputs and BuildingForm.EstimateCostByFloorLevel node in order to include three inputs in which the twist of the building was considered since this will increase construction cost and attractiveness when renting. The node was also modified for efficiency. This same custom node was used to calculate a revenue of the building. Finally, a custom node was created that calculated the Net Present Value considering discount rates and number of years considering that the revenue is received as an annuity (common in bond payments used for big projects). With these results, we calculated the IRR to have more financial metrics. A custom node called Evaluate Revit Model was created (modified the BuildingForm.EvaluatePairsOfInputsAndReportMultipleResults) in order for efficiency.
In this case, the selected project is that of Height 300 ft and twist of 80. This yielded a NPV of 55 million dollars when considering a lifetime of 40 years and discount rate of 3% (lets ignore the current inflation rate for this exercise).
The Dynamo logic is as follows:
This is where the user inputs the information.
We set the building constants and Pack the Information.
The optimization Ranges and List of Alternatives is created.
The Alternatives are evaluated in the custom node and exported to excel.
The EvaluateRevitModel node is the BuildingForm.EvaluatePairsOfInputsAndReportMultipleResults modified to include more inputs (Cost and Revenue) and report more output values as seen below:
As seen above, the EvaluateRevitModel also includes Cost and Revenue Calculation by modifying the BuildingForm.EvaluateValueByFloorAreaForTwoInputs two include 3 outputs (twist), Net Present Value Custom Node, SA/Volume Ratio and IRR.
The BuildingForm.EvaluateValueByFloorAreaForThreeInputs has one additional Input and the BuildingForm.EstimateCostByFloorLevel was modified to include the twist.
As seen below, the BuildingForm.EstimateCostByFloorLevel was modified to include the twist in the cost and revenue calculations (Twist is more expensive to build but more attractive to buyers).
Finally, the Net Present Value custom node calculated the NPV considering that future payments will be equal in the form of annuities. This form of payment is like bonds and is used to finance big projects.
