Original design:
Introduction: The purpose of this assignment is to give advice to the developers of a new high-rise building. I assumed this building will be a commercial property. I focused on three metrics to evaluate my alternatives: the building’s present worth, percentage of clear and unobstructed view, and space efficiency. I think developers will care a lot about how much will the building cost to be built, and how much profit the building can generate in the long term. To demonstrate this concept, I found the total construction cost and annual office rent. By assuming an inflation rate, an interest rate, and a service life of 50 years, I used the uniform series present worth method to obtain the present worth of the building alternatives. Details will be shown later. In additional to cost, I also found the percentage of clear and enjoyable view that the building could offer to people when they are standing near the window and looking out. Furthermore, I used gross volume/gross floor area to obtain the space efficiency factor; if this factor is high, the building will feel more spacious. These two factors can be used to advertise for the building to attract more renters. To model the buildings around the project site, I went on Google Maps to get a sense of how the buildings were located and oriented around the site, and how tall they were. The tallest building nearby was 420 ft high, so almost all the buildings in close proximity to the site were lower than the project building. The surrounding buildings were created as in-placed mass.
New metric 1: building present value Before I created a custom node, I lay out my logic and made sure it worked for individual cases. First, I obtained the mass floor areas by laying out the logic and I compared them to the results obtained from using the custom node, BuildingForm.MassFloors, to make sure the results matched. The logic in the custom node is exactly the same as the laid out logic.
Then, I assumed the following values for estimating the building’s worth. The building cost was provided in the assignment description. I found that the average office rent per SF in San Francisco was $87 per month. Therefore, I assumed the annual rent for the lowest floor was $720 per SF and for the highest floor was $1080 per SF (class A and class B mixed offices). https://www.commercialcafe.com/office-market-trends/us/ca/san-francisco/ I also assumed a rate of inflation of 8.5%, an interest rate of 5%, and a service life of 50 years.
I obtained the total construction cost and the annual rental income. Then, by using the equation: InflationRate+AnnualInterestRate+InflationRate*AnnualInterestRate, I obtained the inflation adjusted interest rate.
Next, I removed the nulls from the list. And by using the uniform series present worth equation, (P/A, i%, n), P=A*[(i+1)^n-1]/[i*(1+i)^n], I obtained the present value of the rent income, and by subtracting the construction cost from it, I can obtain the present worth of the whole building.
After I made sure the calculation was correct, I copied the logic and created a custom node to estimate the building worth. The logic in the custom node is exactly the same as the laid out logic.
New metric 2: clear view analysis (using lines of sights) For the second metric, my inputs are listed below. I chose 6 and 10 to be the numbers of panels in the U and V direction to panelize the building. The number of lowest V panels to be excluded is 3, and the length of sight lines is 2000.
After the building was panelized, the normal vectors of the panels were obtained and extended to intersect with the surrounding buildings. By summing the number of lines of sight that did not intersect with the surrounding buildings and dividing that number by the total number of lines of sight, I was able to obtain the percentage of clear view.
After making sure the calculation was correct, I modified the custom node created by the class example and compared the results obtained from using both methods to make sure they matched.
Modification on the big evaluation node: After the two metrics were created successfully, I integrated them into the big evaluation node, so that multiple cases could be run. The logic here is the same as in last assignment, using Cartesian product to obtain input pairs, and loop them into List.Map node to run all the cases.
This node is modified based on the custom node created in last assignment.
Additional inputs within the node:
The new custom nodes were incorporated into the big evaluation node.
The gross floor area, surface area, and volume values were obtained. I used gross volume/gross floor area to obtain the shape efficiency, which is my third metric.
Here are the outputs of the evaluation node.
After the results are obtained, all of them will be exported to Excel.
After the results are obtained, they will be evaluated. The three metrics that are being evaluated are: space efficiency, building present worth, and percentage of clear view. I modified the EvaluationResults.ComputeCombinedEvaluationScore to perform my evaluation.
Within the custom node, I rescaled the results, so they were all between 0 and 1. Then I put weighted factors for the three metrics to demonstrate their degrees of importance. Then, I added the weighted scores together.
I wanted the total score to be 100. Therefore, I used 20, 50, and 30 as the weighted factors for space efficiency, building present value, and percentage of clear view, respectively. The building value is the most important factor because this is why the developers want to develop this building, to make profits. Then, the percentage of clear view and space efficiency are both good advertising points. Renters might be more interested in knowing if the building can offer them great city view. After the combined scores for all alternatives are obtained, they will be export to Excel.
Metric Results & evaluation scores for all alternatives: The three columns with boded values are used for evaluation. Alternatives with the three highest combined scores are CASE 4 (75.02), CASE 3 (73.46), CASE 5 (70). These three alternatives offer the most gross floor area, surface area, and volume. They also cost the most money to be built. However, they also generate more profit in a long term; therefore, they have higher building present worth. It is interesting that even though CASE 5 has a higher monetary value, it has the lowest scores among the three. The reason is because that it does not offer as much unobstructed city view as the other two alternatives do.
I will recommend CASE 4 to my clients because it has the highest combined score. It is profitable, and at the same time, can offer great city view and spatial comfort to its users. Therefore, the building with a mid-rotation of 100 degrees and a mid-width of 120 ft will be the best option.
Best alternative rendering (it is a little “fatter” than the original design):
