Revit conceptual mass family from the CEE 120C/220C Shared Library, placed in a Dubai-located project file with 50 levels at 13 ft floor-to-floor (650 ft total height). Mass floors assigned to all 50 levels for GFA calculation.
Fixed parameters: Twist 45°, Top Depth 50', Base Width 200', Base Depth 100', Building Height 650'
Variable input flexed: Building Top Width
Test Results
Case | Top Width | GFA (SF) | Surface (SF) | Volume (CF) | GFA/Surface |
1 | 200' | 682,561 | 370,713 | 8,798,097 | 1.84 |
2 | 175' | 647,717 | 354,009 | 8,335,756 | 1.83 |
3 | 150' | 612,543 | 337,437 | 7,873,414 | 1.81 |
4 | 125' | 578,030 | 321,024 | 7,411,073 | 1.80 |
5 | 100' | 543,186 | 304,807 | 6,948,731 | 1.78 |
6 | 75' | 508,342 | 288,842 | 6,486,389 | 1.76 |
Observations: Each 25 ft reduction in top width drops GFA by ~35,000 SF, surface area by ~16,000 SF, and volume by ~462,000 CF. The GFA-to-surface ratio decreases slightly with increased taper (1.84 → 1.76), indicating a uniform tower form is marginally more envelope-efficient than a strongly tapered one.
Stage 1 Part 2 — Custom H_Twist_Mass Conceptual Mass Family
Custom Revit conceptual mass authored by pasting an H-shaped profile into the provided Twisting Tower template, then lofting between H profiles at base and top reference levels. Building height: 595 ft (~45 functional floors at 13 ft floor-to-floor).
Form concept: Twin-tower with mid-height sky bridge — two parallel masses connected by a 22m-thick crossbar.
Fixed parameters: Top Rotation 90°, Base Rotation 10°, Top Width 50', Top Depth 20', Top Height 100', Base Width 300', Base Depth 200'
Variable input flexed: Number of office floors (study: how does reallocating floors to non-office uses affect total office GFA?)
Test Results
Case | Office Floors | Non-Office Floors | % Non-Office | Office GFA (SF) | Surface (SF) | Volume (CF) | Compliant (2.5–3M SF)? |
1 | 38 | 7 | 16% | 2,410,112 | 933,881 | 38,543,110 | No - under |
2 | 40 | 5 | 11% | 2,536,960 | 933,881 | 38,543,110 | Yes |
3 | 42 | 3 | 7% | 2,663,808 | 933,881 | 38,543,110 | Yes |
4 | 44 | 1 | 2% | 2,790,656 | 933,881 | 38,543,110 | Yes |
5 | 46 | 0 (over capacity) | — | 2,917,504 | 933,881 | 38,543,110 | Yes |
6 | 48 | 0 (over capacity) | — | 2,980,928 | 933,881 | 38,543,110 | Yes |
Observations: Each pair of floors reallocated from office to non-office use reduces office GFA by ~126,848 SF. Gross Surface Area and Gross Volume remain constant — they describe the form's fixed exterior envelope. Recommended program: Case 3 (42 office floors, 3 non-office floors) — delivering 2.66M SF of office space while reserving floors for ground-floor lobby/retail, mid-height sky lobby/amenity, and one mechanical floor.
Note: The custom H profile geometry was not parametrically bound to the template's dimensional reference planes. Template parameters (Top Width, Base Width, etc.) display in Properties but do not actively drive the H profile shape — a known Revit family editor limitation when introducing non-template profile shapes.
Stage 2 & 3 — Parametric H Tower in Grasshopper (Final Recommended Form)
Custom H-shaped profile authored as a Grasshopper cluster, lofted into a tapering, 90° twisting tower. The 12-point H polyline is parametrically defined by W (overall width), H (overall depth), L (leg width), and B (crossbar thickness).
Form concept: Twin-tower with mid-height sky bridge, twisted 90° from base to crown, tapering from base to top.
Fixed parameters: W = 121m, H = 60m, L = 55m, B = 22m, floor height = 4m, twist total = 90°
Variable inputs flexed (12 cases): numFloors (50, 53, 56) × taperRatio (0.5, 0.6, 0.7, 0.8)
Stage 2 Test Results
Case | numFloors | taperRatio | Footprint (m²) | GFA (m²) | GFA (SF) | Surface (m²) | GFA/Surface |
1 | 50 | 0.5 | 6,842 | 199,849 | 2,151,193 | 74,291 | 2.69 |
2 | 50 | 0.6 | 6,842 | 223,692 | 2,407,927 | 79,410 | 2.82 |
3 | 50 | 0.7 | 6,842 | 249,838 | 2,689,389 | 84,710 | 2.95 |
4 | 50 | 0.8 | 6,842 | 278,288 | 2,995,591 | 90,198 | 3.09 |
5 | 53 | 0.5 | 6,842 | 211,822 | 2,280,019 | 78,158 | 2.71 |
6 | 53 | 0.6 | 6,842 | 237,102 | 2,552,141 | 83,536 | 2.84 |
7 | 53 | 0.7 | 6,842 | 264,822 | 2,850,464 | 89,092 | 2.97 |
8 | 53 | 0.8 | 6,842 | 294,982 | 3,175,025 | 94,834 | 3.11 |
9 | 56 | 0.5 | 6,842 | 223,796 | 2,409,046 | 82,033 | 2.73 |
10 | 56 | 0.6 | 6,842 | 250,512 | 2,696,646 | 87,670 | 2.86 |
11 | 56 | 0.7 | 6,842 | 279,805 | 3,011,915 | 93,483 | 2.99 |
12 | 56 | 0.8 | 6,842 | 311,677 | 3,355,084 | 99,479 | 3.13 |
Stage 3 Performance & Economic Analysis
Case | nF | TR | GFA (SF) | GFA/Surf | Avg $/SF | Total Cost | Insolation (MWh/yr) | Compliant? |
1 | 50 | 0.5 | 2.15M | 2.69 | $719 | $1.55B | 111,437 | No - under |
2 | 50 | 0.6 | 2.41M | 2.82 | $719 | $1.73B | 119,115 | No - under |
3 | 50 | 0.7 | 2.69M | 2.95 | $719 | $1.93B | 127,065 | Yes |
4 | 50 | 0.8 | 3.00M | 3.09 | $719 | $2.15B | 135,297 | Yes |
5 | 53 | 0.5 | 2.28M | 2.71 | $732 | $1.67B | 117,237 | No - under |
6 | 53 | 0.6 | 2.55M | 2.84 | $732 | $1.87B | 125,304 | Yes |
7 | 53 | 0.7 | 2.85M | 2.97 | $732 | $2.09B | 133,638 | Yes |
8 | 53 | 0.8 | 3.18M | 3.11 | $732 | $2.32B | 142,251 | No - over |
9 | 56 | 0.5 | 2.41M | 2.73 | $745 | $1.79B | 123,050 | No - under |
10 | 56 | 0.6 | 2.70M | 2.86 | $745 | $2.01B | 131,505 | Yes |
11 | 56 | 0.7 | 3.01M | 2.99 | $745 | $2.24B | 140,225 | No - over |
12 | 56 | 0.8 | 3.36M | 3.13 | $745 | $2.50B | 149,219 | No - over |
Best in each category (compliant cases only — 3, 4, 6, 7, 10):
- Best envelope efficiency: Case 4 (GFA/Surface = 3.09)
- Highest insolation potential: Case 7 (133,638 MWh/yr)
- Lowest construction cost: Case 3 ($1.93B)
- Highest GFA achieved: Case 4 (3.00M SF)
Final Recommendation: Case 4 — 50 floors, taperRatio = 0.8, 200m height, 3.00M SF, $2.15B construction cost. Highest envelope efficiency among compliant cases (3.09), shortest compliant building height (minimizing construction cost), full program fulfillment at the 3M SF ceiling, and architecturally distinctive form appropriate for Business Bay's high-profile site adjacent to the Burj Khalifa.