Annalena Bellm: 2 Units
Original Building Form:
Optimized Building Form:
When completing this assignment I wanted to put myself into the shoes of a client. As a structural engineer I think its easy to put your full concentration into efficiency. Though this is important, clients often think of one thing: revenue. Since I wanted my client to have a little more of a conscience, I decided to make my two custom nodes expected building revenues and expected embodied carbon. To do this, I customized the provided BuildingForm.EvaluateSingleInput custom node provided to output an additional factor besides gross floor area and gross surface area.
Overall Script used:
First Node: Building Expected Revenue
In order to estimate the building revenue, I calculated the total expected construction cost using the linear function: C(x) = 750 + (1500-750)/750*x. This function estimates the building construction cost which varies linearly as the building height increases. Then, I calculated the estimated income in rent the building could expect over its service life. I once again estimated a linear relationship of rent per unit with height as: R(x) = 850 + (3500-850)/750*x. This function assumes a rental income of $850 per unit at the base of the building, which increases linearly with height to $3500 per unit at the penthouse. I estimated 9 units per story, which provides ample space for a concrete core, mechanical space, elevators, etc. in the building. Then, to find the net revenue, I estimated a 50 year service life with 50% of rental income going to building maintenance, repairs, and taxes. This net revenue was calculated for each potential building height and summarized in a table.
Second Node: Building Expected Embodied Carbon
Since I wanted my client to not only think of potential earning but also carbon emissions during construction, I created a custom node that would estimate the building’s embodied carbon. To do this, I assumed the building would be a concrete core building with reinforced concrete slabs and a steel gravity system. Using The Shard in London as a model of a mixed material building, I estimated the slabs to be 7 inches thick made out of reinforced concrete with 10 inch thick shear walls. Then I estimated the total amount of steel present in the building using a linear interpolation using the amount of steel in the Shard and it’s height as the estimating for my building. I then added the carbon embedded in the steel with that of the concrete to estimate the expected embodied carbon due to the two major construction materials in the building. I then outputted this value and summarized it in a table shown below.
Table summarizing outputted values:
Using these two measures, it can be seen that given these estimations and assumptions, the best building height would be 640 ft or 662 ft. At these two heights the exchange between building revenue and tons of embodied carbon make an exchange. Therefore, I would suggest a building height of 662 ft with an estimated $609M revenue over its lifetime and 15k tons of embodied carbon emissions during construction.
Sources:
https://www.greenconcrete.info/downloads/11_ConcreteCO2.pdf
http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=1447