Hana Thibault

1. Erection Cost vs Real Estate Value
1. Design Variables: Height, Width, Depth
2. Evaluators: Amount of steel in the building construction, Square footage of the building
3. Tradeoffs: As the height and floorplan of the building increase, the erection cost increases but the amount of leasable space in the building also increases means that the real estate value increases.
2. Embodied Carbon vs Material Cost
1. Design Variables: Type of Building Material, Height of Building, Width of Building, Depth of Building
2. Evaluators: Amount of Material Used in the Building, Embodied Carbon per Volume of Material, Cost per Volume of the Material
3. Tradeoffs: It is likely (but not always true) that as the amount of embodied carbon in the material increases, the price will most likely decrease. A more sustainable project often means higher overall project costs.
3. Construction Man Hours vs Complexity of Design
1. Design Variables: Height, Depth and Width of the building, Floorplan layout
2. Evaluators: Number of individual beams and connections for implementation
3. Tradeoffs: As the complexity of the design increases, this also will increase the number of construction man hours required. Complexity in the design is often desired by architects and clients whereas they would also like the lowest cost possible which requires a lower number of manhours on the project.

Steel erection is a very important step in the life of a building as it informs the form of the building and how the building reacts to its external environment. When thinking about the shape of the building, there are many topics the architect and owner need to discuss. This includes whether they want to put more money into the project at the start in order to reap more in the future, or if they are happy to invest less now but also gain less in the future. Based on this decision, the width, depth, height and number of bays in the building will be modified. The more the dimensions of the building increase, the more expensive it becomes initially but the client will reap more benefits in the future. When it comes to the bay size, less bays are optimal as the number of bays informs the number of columns. The less columns there are per square foot of the building means that there will be more open space leading to a more premium cost for renting. This was all taken into consideration when designing the system. The cost of the perimeter steel was determined by the depth, height and width of the building with each floor containing two beams that span the width and two that span the depth. The erection cost was based on the number of floors in the building and the addition of each additional floor increased in price as the building got taller due to the need for larger cranes. The number of bays was determined by the maximum clear span, width and depth of the building with a lower number of bays being optimal. Lastly, the real estate value was based on the square footage of the building as determined by the width and depth with floors at higher elevations being worth more because of the potential for a view in the building.

• Material Cost vs Number of Bays vs Erection Cost vs Real Estate Value
1. Design Variables: Height, Width, Depth, Max Clear Span of Bays
2. Evaluators: Amount of Material, Number/Size of Bays
3. Tradeoffs: As the height, depth and width of the building increase, the material cost and erection cost will increase but the real estate value will also increase. As the max clear span increases, the number of bays decreases which is optimal for real estate value to decrease the number of columns in the building. A full list of the tradeoffs can be seen below.

Scatterplots:

Figure 1. Scatterplot of Material Cost Versus Real Estate Value

As can be seen in the scatterplot above, as the real estate value of the property increases, the material cost also increases meaning that a direct relationship can be seen. This relationship is not linear though, as the real estate value of the property increases, the amount the material cost increases per unit of increase in the real estate value also increases. This implies that to a certain extent, the additional investment in materials to make a larger building is impactful until around $75,000 of investment in materials when the price shoots up meaning this is the optimal height to build to if wanting to get the most bang for one’s buck.

Figure 2. Scatterplot of Erection Cost Versus Real Estate Value

Figure 2 shows that as the real estate value of the building increases, the erection cost of the building also increases. This is similar to the scatterplot above of the material cost though this increase is much more dramatic. This mimics what is seen in the real-world because taller buildings require more specialized construction but also larger members which require larger cranes for lifting. When looking at this graph, the erection cost starts to increase in a major way once about 15 million dollars is reached in real estate value. Because of this, it is optimal for the building planning team to keep this metric in mind to avoid investing too much money upfront in construction and not reaping the full benefits of the space in terms of real estate value in the future.

Figure 3. Scatterplot of Number of Bays Versus Real Estate Value

Figure 3 shows an unexpected trend. It shows that as the real estate value of the building increases, the number of bays in the building should either decrease or stay the same. This is most likely due to the fact that this algorithm did not account for comparing buildings which have more bays but a larger footprint with buildings that have less bays but also a smaller floor plan. In the future, a better metric than number of bays would be comparing the square footage per bay rather than the exact number of them. Nonetheless, it is expected that the real estate value would increase with a decreased number of bays as this means that there are less columns present in the building which leads to the availability of more open spaces which exude more lux and can be charged a higher price tag. If the contractor wants to increase the real estate value in this building, the number of bays should be kept at a minimum and the clear span should be kept at a maximum.