Chloe Leung

Chloe Leung

2 Units Part 1:

To begin, a conceptual mass was created in Revit using the Parametric Tower – Twisting Rounded Triangular Mass (Shanghai Tower Proportions) template. This massing model includes adjustable parameters such as top height, top rotation, top radius, mid radius, mid height, base rotation, and base radius. By default, the mid rotation and mid radius are governed by the formulas:

  • mid rotation = (top rotation - base rotation) / 2
  • mid radius = top radius + (base radius - top radius) / 2

To ensure a more symmetrical design, an additional constraint was applied:

  • top radius = ½ × base radius

Floors were added at 15-foot intervals along the building’s height.

To evaluate how different parameters impact the gross floor area, gross surface area, and gross volume, the top rotation was varied from 100° to 160° in 10° increments, while keeping the remaining parameters constant:

  • top height = 750'
  • base radius = 190'
  • base rotation = 0°

All other dependent parameters were calculated based on these fixed inputs. The two images below illustrate how changes in top rotation affect the overall geometry. The first image shows the tower with 100° of rotation, while the second image shows the same form with 160° of rotation.

image
image

Although the visual difference is subtle, the 160° rotation model exhibits greater overall twisting. A parametric study was conducted to evaluate how this increase in rotation impacts key performance metrics. As shown in the summary table, increasing the top rotation generally leads to a decrease in gross floor area, gross surface area, and gross volume, helping inform design decisions related to building efficiency and form optimization.

Top Rotation (degrees)
Gross Floor Area (SF)
Gross Surface Area (SF)
Gross Volume (CF)
100
2862398.244
760500.4388
42273222.35
110
2836956.486
758450.0555
41890902.01
120
2806426.625
755896.0876
41432348.46
130
2770459.437
752807.2376
40891696.8
140
2728807.837
749167.1709
40265404.69
150
2681340.344
744971.9234
39551696.5
160
2628055.174
740236.2643
38750629.85

2 Units Part 2:

Next, a custom building form was developed using two square profiles with adjustable side lengths and a circular profile with an adjustable radii, which were lofted to create the tower geometry. Parameters that can be flexed include the base, top square lengths, middle profile circle radii, as well as the heights of the middle and top profiles. For this parametric study, the middle radius was tested in 5’ increments, ranging from 115’ to 140’. Images of the building at 115’ radii and 140’ radii are shown below.

image
image

As expected, the summary table below shows that gross floor area, gross surface area, and gross volume all increase with a greater mid tower radius.

Mid Radius (Ft)
Gross Floor Area (SF)
Gross Surface Area (SF)
Gross Volume (CF)
115
2525375.434
800264.8745
37488264.42
120
2652349.378
818107.5758
39392784.26
125
2783346.132
836040.4293
41357517.95
130
2918355.324
854066.4677
43382465.51
135
3057382.289
872188.8309
45467626.92
140
3200418.85
890410.7465
47613002.19

Points to Ponder: Exporting the results to Excel provides several advantages. It ensures that results are automatically updated with each parameter change, making it an efficient tool for iterative design. Metrics can be quickly sorted and filtered to identify maximum and minimum values, allowing designers and clients to easily pinpoint the most optimal parameters for an efficient building. Additionally, exporting to Excel provides clear documentation of all test cases and results, and enables easy visualization through charts and graphs—supporting both technical evaluation and communication with stakeholders.

3 Units:

For this stage, a custom building form was created in Dynamo. The bottom and top profiles are equilateral triangles, while the middle profile is circular. There was no specific design precedent for this form—it was developed out of curiosity to explore how the geometry would respond as parameters varied. Input parameters include the size of both equilateral triangles, the radius of the middle circle, the rotation of each triangle, and the middle and top heights of the structure. To allow flexibility in the form, the top and bottom triangles were intentionally not constrained to be dimensionally symmetrical.

For the parametric study, all parameters were held constant except for the mid-height circle radius and top height. The circle radius was varied from 135’ to 150’ in 5’ increments, while the top height ranged from 690’ to 720’ in 10’ increments. The first image below shows the structure with a circle radius of 135’ and height of 690’, while the second shows a radius of 150’ and height of 720’.

image
image

Again, the outcome of the study aligns with expectations, as all performance metrics—gross floor area, surface area, and volume—increase with larger circle radii and greater building heights. Notably, the final two trials clearly exceed the allowable gross floor area, immediately indicating that these parameter combinations are unsuitable for the building design. This further illustrates the value of exporting results to Excel, where such violations can be quickly identified and analyzed to allow informed decision-making.

Mid-Height Circle Radius (Ft)
Top Height (Ft)
Gross Floor Area (SF)
Gross Surface Area (SF)
Gross Volume (CF)
135
690
2448789.75
536726.7669
30286057.83
135
700
2488224.773
544780.9212
30759804.32
135
710
2520014.628
552898.8354
31238666.51
135
720
2560458.3
561080.4975
31722630.59
140
690
2608926.397
553732.2366
32288073.47
140
700
2651847.966
562098.6494
32805530.1
140
710
2687205.69
570532.9088
33328854.29
140
720
2731272.047
579034.9074
33858031.27
145
690
2774695.572
570942.8534
34360498.59
145
700
2821248.055
579621.3951
34923464.17
145
710
2860320.643
588371.9789
35493091.3
145
720
2908160.029
597194.4027
36069364.78
150
690
2946033.579
588358.5878
36502532.9
150
700
2996355.512
597348.7164
37112742.49
150
710
3039285.183
606415.1771
37730447.92
150
720
3091042.331
615557.6742
38355634.13
Average
2758367.528
575293.5318
34177214.04

Points to Ponder: The performance metrics are more sensitive to changes in the circle radius than to changes in the top height. For example, when the top height is held constant at 690’, increasing the circle radius from 135’ to 140’ results in an increase in gross floor area of approximately 160,136 SF. In contrast, when the circle radius is fixed at 135’, increasing the top height from 690’ to 720’ results in a smaller increase of about 111,668 SF in gross floor area. This suggests that modifying the circle radius has a greater effect on building performance than altering the building height. To further validate these observations, results can be graphed or statistically analyzed to ensure that these trends are consistent for a larger testing range.

4 Units:

An additional performance metric used to assess building efficiency in the 3-Unit model is the ratio of Gross Floor Area to Gross Surface Area. This ratio provides insight into how effectively the envelope encloses usable space. For example, when the structure has a circular radius of 135 feet and a height of 690 feet, the efficiency is 4.56. In comparison, increasing the radius to 150 feet and the height to 720 feet results in a slightly higher efficiency of 5.02.

Mid-Height Circle Radius(Ft)
Top Height (FT)
Gross Floor Area (SF)
Gross Surface Area (SF)
Gross Volume (CF)
Efficiency
135
690
2448789.75
536726.7669
30286057.83
4.562451327
135
700
2488224.773
544780.9212
30759804.32
4.567386038
135
710
2520014.628
552898.8354
31238666.51
4.557822275
135
720
2560458.3
561080.4975
31722630.59
4.563441987
140
690
2608926.397
553732.2366
32288073.47
4.711530636
140
700
2651847.966
562098.6494
32805530.1
4.717762566
140
710
2687205.69
570532.9088
33328854.29
4.709992445
140
720
2731272.047
579034.9074
33858031.27
4.7169385
145
690
2774695.572
570942.8534
34360498.59
4.859848154
145
700
2821248.055
579621.3951
34923464.17
4.867398062
145
710
2860320.643
588371.9789
35493091.3
4.861415474
145
720
2908160.029
597194.4027
36069364.78
4.869704097
150
690
2946033.579
588358.5878
36502532.9
5.007207577
150
700
2996355.512
597348.7164
37112742.49
5.016090987
150
710
3039285.183
606415.1771
37730447.92
5.011888386
150
720
3091042.331
615557.6742
38355634.13
5.021531629
Average
2758367.528
575293.5318
34177214.04
4.788900634

Points to Ponder: If the primary design objective is to maximize efficiency, then a circular radius of 150’ and a building height of 720’ would lead to the most desirable result. However, it’s important to acknowledge that this configuration would likely lead to higher construction costs. Therefore, determining the “best” structure ultimately depends on the developer’s priorities. If efficiency is the main concern, this combination would be the recommended option.