Journal Entry For
Module 6 - Evaluate Your Alternatives
Link to Student
- For 2 or More Units: Create Two New Evaluator Nodes
- For this module I created two new evaluator nodes: 1) comparison of construction cost by thirds of the building and 2) the building’s total direct sun hours for January (since it has the lowest average sunlight hours out of the months of the year for Dubai)
- Evaluator node 1:
- Evaluator node 2:
- Summary Table:
- Note that the floor area values can be scaled by a little over 30x to get the desired SF, I reduced the size of my geometry to keep processing time low
- Points to Ponder: Do the new evaluation metrics that you’ve designed capture the meaningful differences between the building form alternatives?
- I believe they do—they directly address the brief points around understanding cost and solar insolation.
- What other metrics would be useful to compute to help understand and make the case for which alternatives are truly better than others?
- There’s a large variety of metrics that could be investigated. Here’s a few that could be important:
- Percentage of the structure that receives some threshold amount of sunlight
- Directness/obscuration of view
- Wind load
- For 3 or More Units: Develop a Single-Objective Optimization Scheme
- My Single-Objective Optimization Scheme (combination/comparison/ranking approach)
- For my SOO scheme, I decided to start with the assumption that cost would be the most important factor to the developers, followed by amount of direct sun hours which is related to solar insolation.
- To normalize the values at hand, I took the total floor area cost and direct sun hour values and remapped them between 0-10. I constructed the domains such that ‘10’ would signify the most desirable outcome.
- For the floor area cost, a lower cost was mapped to a higher value
- For the sun hours, more sun hours would map to a higher value
- To reflect the priority I described above, I then multiplied the normalized values by a scaling factor to weight the priority.
- The priority values are adjustable, but I set the cost weight to 3, and the sun hour weight to 2
- After setting the priority, I incorporated my % cost by building thirds metric by first evaluating a score in my spreadsheet and adding that to the above evaluated values
- I compared the relative percent cost of constructing the first third of the building against the last two thirds. If it was more expensive to construct the last two thirds, I assigned a less desirable score of -1, if less expensive, I assigned a score of 1
- The thought was that it might be harder for developers to raise increasing amounts of capital, especially if they exceed initial costs. Additionally, re floor area, given the structure of the tower, there’s less cost benefit as the tower grows in height.
- Finally I took the rough SOO scores and remapped and rounded them a final time to be between 0-10 to be able to evaluate the ‘best alternatives’ at a glance. The top 3 are highlighted in blue on the summary table below.
- Summary Table (Optimized forms scored from 0-10 with 10 being the most recommended)
- The building highlighted in the darkest blue, with a score of 10 is the ‘best’ choice according to my SOO scheme. Of the building configurations tested, this one was the second cheapest to construct, had the highest number of sun hours, and had a favorable construction timing—given the parameters of my scheme, this configuration best maximized the values I put up for evaluation/ranking.
- Point to Ponder: What propelled the recommended alternative to the top of the list. Explain your reasoning -- include a brief analysis of why this alternative rose to the top of the list and why you consider it to be the best option.
- This is addressed above, but the high sun hour value (~1.3x the second highest sun hour value) definitely affected the ranking.
- Are there important nuances or tradeoffs that got lost is the single evaluation?
- There was a much larger spread among the sun hour values that likely skewed the rankings. It’s possible also, that after a certain threshold of sun hours is hit, it wouldn’t be necessary to continue to maximize this metric.
- For 4 Units: Visualize the Recommended Alternative
- Your answers to the Points to Ponder questions for each stage of the assignment that you completed.