(a) Upper-Level Setbacks. Setbacks of the upper parts of a building abutting a public sidewalk in any C-3 District may be required, in accordance with the provisions of Section 309, as deemed necessary:
(1) To preserve the openness of the street to the sky and to avoid the perception of overwhelming mass that would be created by a number of tall buildings built close together, with unrelieved vertical rise; or
(2) To maintain the continuity of a predominant street wall along the street, provided however, that the setback required pursuant to this Paragraph may not exceed the following dimensions:
Street Width | ||||
64' - 67' | 68' - 71' | 72' - 75' | 76' - 80' | |
Height of Street Wall | Depth of Setback (In Feet) | |||
68' or less | 18' | 20' | 22' | 24' |
69' - 81' | 14' | 16' | 18' | 20' |
82' - 94' | 10' | 12' | 14' | 16' |
95' - 107' | 8' | 10' | 12' | 14' |
108' - 120' | 6' | 8' | 10' | 12' |
(b) Market Street Setback. In order to preserve the predominant street wall, structures on the southeast side of Market Street between the southerly extension of the easterly line of the Powell Street right-of-way and Tenth Street shall be set back 25 feet from the Market Street property line at 90 feet.
(c) C-3-O(SD) District.
(1) Streetwall Base. In order to establish an appropriate street wall in relation to the width of the street and to adjacent structures and to avoid the perception of overwhelming mass that would be created by a number of tall buildings built close together with unrelieved vertical rise, new buildings taller than 150 feet on development lots in the C-3-O(SD) district facing a street wider than 35 feet shall establish a distinctive streetwall, even where no distinct cornice line or streetwall exists, at a height between 50 and 110 feet for not less than 40 percent of the linear frontage of all street frontages of such development lot. Such streetwall shall be established, by an upper story setback or by a combination of upper story setback and horizontal projection (either occupied or decorative, as allowed in Section 136), creating horizontal relief totaling at least 10 feet, however the upper story setback shall not be less than 5 feet. In the New Montgomery-Mission-Second Street Conservation District, such streetwall height shall be set by the prevailing cornice line of the buildings on the subject block face and the minimum dimension of the upper story setback shall be increased to not less than 15 feet. Exceptions to this subsection (c)(1) may be allowed in accordance with the procedures of Section 309 if the Planning Commission affirmatively determines that all of the following criteria have been met:
(B) the base is not defined solely by recessing the base,
(C) the overall building mass tapers or steps away from the street above the streetwall reducing any sense of unrelieved vertical rise directly from the sidewalk edge, and
(D) the overall architectural expression of the proposed project is exceptional, unique, and consistent with the intent of the streetwall requirement.
(2) Pedestrian Zone. In order to establish an appropriate and inviting relationship to the pedestrian realm at street level and create visual and varied interest for pedestrians, all new structures in the C-3-O(SD) district shall incorporate architectural features, awnings, marquees, or canopies, that project from the building face at least one foot at height of between 15 and 25 feet above grade, for at least 20 percent of the linear frontage of all street facing facades.
(3) Building Setbacks. In order to provide necessary and sufficient area for pedestrian circulation, building facades on new development facing certain street frontages are required to be setback from the street-facing property line.
(A) Building setbacks are required on the following frontages:
(i) Mission Street, south side, between 1st and Fremont Streets (minimum 12.5 feet).
(B) A setback of up to 10 feet may be required by the Planning Commission pursuant to the procedures of Section 309 on the following streets if the Commission finds that such setback is necessary, desirable and will not result in an undesirable sawtooth condition of building frontages along the sidewalk due to existing intervening building between the subject lot and the nearest street corner:
(i) Mission Street, north side between 1st Street and Anthony Street;
(ii) 1st Street, west side between Mission and Stevenson Streets;
(iii) Howard Street, north side, between 1st and 2nd Streets.
(C) Design Requirements. Setbacks provided pursuant to this subsection (3) shall be:
(i) Designed and treated as a seamless extension of the adjacent public sidewalk, providing for pedestrian circulation and/or other activities typically expected on a public sidewalk;
(ii) Free and clear of all permanent building elements from sidewalk grade to a minimum height of 35 feet above sidewalk grade, except as otherwise allowed as obstructions over streets according to Section 136 or as allowed by the Planning Department as an exception according to the procedures of Section 309, and
(iii) Available to the public.
(D) The area of setbacks provided pursuant to this subsection (3) shall be counted toward the open space requirements of Section 138. If the subject development does not rely on this area to meet its Section 138 requirements, and the area of the setback is dedicated in fee title to the City for public use or, under exceptional circumstances, dedicated to the City via easement for public use, the value of the setback may be credited as an in-kind improvement toward the satisfaction of the development's fee requirements per Sections 424.6 or 424.7.
(d) Separation of Towers.
(1) Requirement. In order to provide light and air between structures, all structures in the S and S-2 Bulk Districts shall be set back from an interior property line which does not abut a public sidewalk and from the property line abutting the right-of-way of a public street or alley. The setback shall be a minimum of 15 horizontal feet measured from the interior property line or the center of a public right-of-way, as the case may be, beginning at a height which is 1.25 times the width of the principal street on which the building faces, and increasing to the widths indicated in Chart A as the building increases in height. Where there are two or more structures on any lot that are taller than 1.25 times the width of the adjacent principal street(s), each structure above such height shall also be set back from the other structures on the same lot according to Chart A as if there is an assumed interior property line half-way between the closest exterior points of each structure.
Chart A
Separation Between Towers
Separation Between Towers
(2) Exceptions. Exceptions to the requirements of Paragraph (d)(1) above may be allowed in accordance with the provisions of Section 309 as provided below:
(A) Encroachments of building volume on the setback may be approved as follows:
(i) for the portion of the building over 300 feet from the ground, encroachments may be allowed provided that
(1) there are compensating recesses beyond the required setback below and within approximately 100 vertical feet of the encroachment, which recesses are at least equal in volume to the volume of the encroachment, and
(2) it is found that, overall, access to light and air and the appearance of separation between buildings will not be impaired; and
(ii) between the top of the base and 300 feet above the ground encroachments may be allowed provided that
(1) there are compensating recesses beyond the required setback at the same level or within approximately 50 vertical feet above or below the encroachment, which recesses are at least equal in volume to the volume of the encroachment,
(2) that the encroachment extends no more than five feet horizontally into the area otherwise required for a setback,
(3) the encroachment extends for less than 1/3 of the horizontal length of the structure, and
(4) it is found that, overall, access to light and air and the appearance of separation between buildings will not be impaired.
(B) Exceptions may be allowed to the extent that it is determined that restrictions on adjacent properties make it unlikely that development will occur at a height or bulk which will, overall, impair access to light and air or the appearance of separation between buildings, thereby making full setbacks unnecessary. The minimum setback for such facades shall be partially or fully reduced as appropriate by the Planning Commission as an exception according to the procedures of Section 309 for any of the following conditions:
(i) For lots on Assessor's Blocks 3719, 3720, and 3721 which have property lines that directly abut the Transbay Transit Center or directly face it across Minna or Natoma Streets.
(ii) For development lots abutting preservation lots that have transferred all potential development rights according to the procedures of Section 128.
(C) Exceptions may be allowed on lots with a frontage of less than 75 feet provided that
(i) it is found that, overall, access to light and air will not be impaired and
(ii) the granting of the exception will not result in a group of buildings the total street frontage of which is greater than 125 feet without a separation between buildings which meets the requirements of Chart A.
(e) Permitted Obstructions. Obstructions above the horizontal plane or planes of the setback required pursuant to Subsections (a), (b), (c) and (d) which will create limited blockage of light and air and which will not be inconsistent with the purpose of the setback may be permitted within the setback area, in accordance with the provisions of Section 309. Such obstructions may include, but are not limited to, open railings, decorative spires and finials, flagpoles and flags, sparse landscaping, unroofed recreation facilities with open fencing, and unenclosed seating areas.
AMENDMENT HISTORY
Section header amended; new division (c) added and former divisions (c) and (d) redesignated as current divisions (d) and (e); division (d)(1), Chart A, and division (d)(2)(B) amended; Ord. 182-12
, Eff. 9/7/2012. Division (c)(1) amended; divisions (c)(1)(i) through (iv) redesignated as (c)(1)(A) through (D); designation of division (e) corrected; Ord. 56-13
, Eff. 4/27/2013.