R6 R7 R8 R9 In the districts indicated without a letter suffix, for sky exposure plane buildings, the minimum required open space ratio and the maximum floor area ratio for any zoning lot shall be determined by the height factor of such zoning lot as set forth in this Section. Where elected, such floor area ratio shall supersede the floor area ratio provisions of Section 23-22, and apply to all residences, including qualifying affordable housing or qualifying senior housing. The minimum open space required through the application of a minimum open space ratio shall be applied in conjunction with the applicable regulations of Section 23-30 (YARDS, COURTS AND OTHER OPEN AREA REGULATIONS). The obstructions set forth in Section 23-311 shall per permitted in required open space. MINIMUM REQUIRED OPEN SPACE RATIO AND MAXIMUM FLOOR AREA RATIO R6 through R9 Districts In R6 Districts In R7 Districts In R8 Districts In R9 Districts For #zoning Min. Req. Max. Min. Req. Max. Min. Req. Max. Min. Req. Max. lots# with a Open Floor Open Floor Open Floor Open Floor height factor Space Area Space Area Space Area Space Area of Ratio Ratio Ratio Ratio Ratio Ratio Ratio Ratio 1 27.5 0.78 15.5 0.87 5.9 0.94 1.0 0.99 2 28.0 1.28 16.0 1.52 6.2 1.78 1.4 1.95 3 28.5 1.62 16.5 2.01 6.5 2.51 1.8 2.85 4 29.0 1.85 17.0 2.38 6.8 3.14 2.2 3.68 5 29.5 2.02 17.5 2.67 7.1 3.69 2.6 4.42 6 30.0 2.14 18.0 2.88 7.4 4.15 3.0 5.08 7 30.5 2.23 18.5 3.05 7.7 4.55 3.4 5.65 8 31.0 2.30 19.0 3.17 8.0 4.88 3.8 6.13 9 31.5 2.35 19.5 3.27 8.3 5.15 4.2 6.54 10 32.0 2.38 20.0 3.33 8.6 5.38 4.6 6.85 11 32.5 2.40 20.5 3.38 8.9 5.56 5.0 7.09 12 33.0 2.42 21.0 3.41 9.2 5.71 5.4 7.30 13 33.5 2.43 21.5 3.42 9.5 5.81 5.8 7.41 14 34.0 2.43 22.0 3.44 9.8 5.92 6.2 7.52 15 34.5 2.43 22.5 3.42 10.1 5.95 6.6 7.52 16 35.0 2.42 23.0 3.41 10.4 5.99 7.0 7.52 17 35.5 2.42 23.5 3.40 10.7 6.02 7.4 7.52 18 36.0 2.40 24.0 3.38 11.0 6.02 7.8 7.46 19 36.5 2.39 24.5 3.36 11.3 6.02 8.2 7.41 20 37.0 2.38 25.0 3.33 11.6 6.02 8.6 7.35 21 37.5 2.36 25.5 3.30 11.9 5.99 9.0 7.25 For zoning lots with height factors greater than 21, the minimum required open space ratio shall be as set forth in the following table: OPEN SPACE RATIO FOR HIGH BUILDINGS District Minimum Required Open Additional Required Open Space Ratio at Height Space Ratio# for each Factor of 21 Additional Height Factor# R6 37.5 0.5 R7 25.5 0.5 R8 11.9 0.3 R9 9.0 0.4 For these zoning lots, the maximum floor area ratio shall be such as can be attained at the required open space ratio for the height factor.*
- The floor area ratio attainable at a given height factor and a given open space ratio may be computed from the following formula: