Chapter 6 - Special Urban Design Regulations
The regulations of this Chapter shall apply:
(a) in R9 and R10 Districts, to developments, as defined in Section 26-13, as set forth in Section 26-10 (SPECIAL REQUIREMENTS FOR DEVELOPMENTS IN R9 AND R10 DISTRICTS). However, the provisions of Section 26-10 shall not apply within any Special Purpose District or to any Quality Housing building;
(b) in R3, R4 and R5 Districts, to zoning lots with buildings accessed by private roads, as set forth in Section 26-20 (SPECIAL REQUIREMENTS FOR LOTS WITH PRIVATE ROADS), except where such zoning lots:
(1) consist entirely of single-family detached residences;
(2) are accessed by private roads that existed on February 6, 2002; or
(3) are located within lower density growth management areas, in which case the provisions of paragraph (c) of this Section shall apply;
(c) in lower density growth management areas, to zoning lots with buildings accessed by private roads, as set forth in Section 26-30 (SPECIAL REQUIREMENTS FOR LOTS WITH PRIVATE ROADS IN LOWER DENSITY GROWTH MANAGEMENT AREAS);
(d) to developments, enlargements or conversions in all districts, as applicable, as set forth in Section 26-40 (STREET TREE PLANTING AND PLANTING STRIP REQUIREMENTS);
(e) to Quality Housing buildings where supplemental ground floor level rules apply to buildings with qualifying ground floors, as set forth in Section 26-50 (SPECIAL GROUND FLOOR LEVEL PROVISIONS FOR QUALIFYING GROUND FLOORS); and
(f) to all energy infrastructure equipment and accessory mechanical equipment not located within a completely enclosed building, as set forth in Section 26-60 (SPECIAL SCREENING AND ENCLOSURE PROVISIONS).
In R9 and R10 Districts, an application to the Department of Buildings for a permit respecting any development shall include a plan and an elevation, drawn to a scale of at least one-sixteenth inch to a foot, of the new building and buildings on contiguous lots or contiguous blocks showing arcades, street wall articulation, curb cuts, street trees, sidewalk paving, a central refuse storage area and such other necessary information as may be required by the Commissioner of Buildings.
General Purposes
The urban design guidelines are established to strengthen, at street level, the relationship of developments with existing buildings and to improve the quality of the streetscape by:
(a) maintaining the visual continuity of developments at street level;
(b) enhancing the visual character of the neighborhood; and
(c) reducing conflict between pedestrian and vehicular circulation.
In harmony with the general purposes and intent of this Resolution and the general purposes of Section 26-11, the regulations of Sections 26-13 through 26-17, inclusive, are intended to:
(a) guide the location of arcades to assure horizontal continuity of developments with existing building arcades and to maintain visual continuity at street level;
(b) require transparency and/or articulation of front walls to improve the visual quality of the street;
(c) improve the quality of the street environment;
(d) limit the number and location of curb cuts, minimizing undue conflict between pedestrian and vehicular movements; and
(e) eliminate trash on sidewalks by requiring central refuse storage areas within the zoning lot.
Definitions
For the purposes of Sections 26-10 through 26-17, inclusive, the following definitions shall apply:
Contiguous block
A "contiguous block" is a block containing one or more zoning lots separated by a narrow street from the block containing the development.
Contiguous lot
A "contiguous lot" is a zoning lot that shares a common side lot line with the zoning lot of the development.
Development
In addition to the definition of development set forth in Section 12-10 (DEFINITIONS), "development" shall also include an enlargement involving an increase in lot coverage.
Horizontal Continuity
Horizontal continuity regulations set forth in this Section are intended to relate developments with existing buildings, at street level, in order to maintain visual and functional continuity relating to the following aspects.
Arcades
Arcades shall be bonused only where the zoning lot of a development occupies:
(a) the entire street line of a block and when the arcade extends the full length of such street frontage; or
(b) a portion of the street line of a block and the contiguous zoning lot contains an arcade extending the full length of the street frontage, and no walls are existing where the two arcades abut; or where the contiguous zoning lot is vacant. Such arcade shall be located at the same elevation as the existing arcade.
Arcades may be interrupted by a bonusable open space such as a publicly accessible open area.
Street wall articulation
When any building wall of a development that is five feet or more in height adjoins a sidewalk, a public plaza or an arcade, at least 25 percent of the total surface area of such walls between curb level and 12 feet above curb level or to the ceiling of the ground floor, whichever is higher, or to the full height of the wall if such wall is less than 12 feet in height, shall be transparent. The lowest point at any point of any transparency that is provided to satisfy the requirements of this Section shall not be higher than four feet above the curb level.
Door or window openings within such walls shall be considered as transparent. Such openings shall have a minimum width of two feet.
In addition, any portion of such building wall, 50 feet or more in width, which contains no transparent element between curb level and 12 feet above curb level or the ceiling of the ground floor, whichever is higher, or to its full height if such wall if less than 12 feet in height, shall be covered with vines or similar planting or contain artwork or be treated so as to provide visual relief. Plantings shall be planted in soil having a depth of not less than 2 feet, 6 inches, and a minimum width of 24 inches. If artwork is being used, approval by the New York City Art Commission shall be obtained prior to the certificate of occupancy being issued for the development.
Curb Cuts
No curb cuts are permitted on wide streets. Curb cuts are permitted along narrow streets provided that no zoning lot has more than one curb cut on any narrow street frontage.
Additional curb cuts, in excess of one for each narrow street frontage, for zoning lots in excess of 30,000 square feet of lot area, or curb cuts on wide streets for zoning lots that have no narrow street frontage may be allowed, provided that the City Planning Commission and the Department of Transportation certify to the Commissioner of Buildings that such additional curb cuts will not result in conflict between pedestrian and vehicular circulation and will result in a good overall site plan.
An application to the Commission for certification respecting any additional curb cut shall be made on a standard application form for such certification and shall be accompanied by a site plan drawn to a scale of at least one sixteenth inch to a foot, showing the size and location of the proposed curb cut. The Commission shall furnish a copy of the application for such certification to the affected Community Board at the earliest possible stage and will give due consideration to their opinion as to the appropriateness of such curb cuts.
In cases where a zoning lot has no narrow street frontage, the Commission may waive the applicable accessory off-street parking requirements of Section 25-23 (Requirements Where Group Parking Facilities Are Provided).
The parking requirements set forth in Sections 25-21, 25-31 or 36-31 shall not apply to any development for which the Commissioner of Buildings has certified that there is no way to provide the required parking spaces with access to a street in conformity with the provisions of this Section.
All developments shall provide facilities for central trash storage within the zoning lot. Where such facilities are provided outside of a building, such facilities shall be screened by an enclosure containing materials compatible with the materials of the front building wall of the development.
In all cases, there shall be an area for central trash collection provided at the rate of 75 square feet for uncompressed garbage or 50 square feet for compressed garbage for each 10,000 square feet of lot area. Such area shall be ventilated.
The City Planning Commission may, by certification to the Commissioner of Buildings, allow modifications of the requirements of this Chapter. Such modifications will be allowed when the Commission finds that such modifications will enhance the design quality of the development.
To provide for the orderly development of residences that are distant from streets, site planning requirements are established in Sections 26-20 through 26-27, inclusive. The regulations of this Section are intended to:
(a) optimize vehicular access within and among zoning lots containing private roads;
(b) regulate the size of and distance between curb cuts to minimize undue conflict between pedestrian and vehicular movement;
(c) provide for sidewalks to facilitate social interaction and enhance pedestrian safety; and
(d) provide for tree planting along private roads in order to enhance the visual and environmental character of the neighborhood.
Private roads shall consist of a paved road bed constructed to minimum Department of Transportation standards for public streets, including curbs and curb drops. The minimum width of a private road shall be 38 feet from curb to curb along its entire length or, where at least three accessory parking spaces are provided for every two dwelling units and no such spaces are located within the bed of a private road, the minimum width shall be 34 feet. The entrance to any group parking facility may be narrower than such minimum widths for a distance not to exceed 20 feet, and a private road may contain a landscaped median provided the paved width of such private road meets the minimum width required exclusive of such medians. The City Planning Commission may modify the required width of a private road, pursuant to Section 26-26 (Modification and Waiver Provisions).
Curbs shall be provided along each side of the entire length of a private road.
A curb cut, excluding splays, from a street to a private road may be as wide as such private road. Curb cuts providing access from private roads to parking spaces located outside the road bed of the private road shall not exceed a width of 18 feet, including splays.
A minimum distance of 16 feet of uninterrupted curb space shall be maintained between all curb cuts.
A minimum three-foot wide planting strip shall be provided adjacent to and along the entire length of the required curb. Within the required planting strip, one tree of at least three inches in caliper shall be planted for every 25 feet of length of such planting strip.
Driveways are permitted to traverse such planting strips, and utilities are permitted to be located within such planting strips.
A minimum four-foot wide paved sidewalk shall be provided adjacent to and along the entire length of the required planting strips. However, no sidewalk shall be required along that side of a private road that does not have a building wall facing it.
An area open to the sky at least five feet in depth shall be provided between a required sidewalk and any building, except that any driveway or parking space located within such open area shall have a depth of at least 18 feet measured perpendicular to such sidewalk. Such open area shall be planted except for parking spaces and entryways to buildings. Where an open area at least 18 feet in depth is required, overhangs of buildings above the first story that project not more than three feet into the required open area are permitted, provided the lowest level of the overhang is at least seven feet above grade at the face of the building. Supports for such overhang are permitted, provided that the total area occupied by such supports does not exceed 15 percent of the area underneath the overhang.
(a) The City Planning Commission may, by authorization, allow modifications to, or waivers of, the requirements of Sections 26-20 through 26-27, inclusive, provided that:
(1) such modifications or waivers will enhance the design quality of the zoning lot;
(2) any decrease in the required width of the paved road bed is in conjunction with a superior parking plan that would not be feasible with a wider road bed; and
(3) any decrease in the required width of the paved road bed will result in the preservation of existing natural features or a superior landscaping plan that would not be feasible with a wider road bed.
No modification or waiver may be granted which would waive or decrease the width of the paved road bed to less than 34 feet.
(b) The City Planning Commission may, by authorization, allow modifications to, or waivers of, the requirements of Sections 26-20 through 26-27, inclusive, for zoning lots within the Special South Richmond Development District, that:
(1) contain designated open space and a portion of the waterfront esplanade, where such zoning lots:
(i) have been granted an authorization pursuant to Section 107-65 (Modifications of Existing Topography) within one year prior to February 6, 2002; or
(ii) are conditioned upon a restrictive declaration that has received a minor modification by the City Planning Commission; or
(2) are located wholly or partially within Area M and have filed an application for an authorization pursuant to Section 107-69 (Residential Uses in Area M) within one year prior to February 6, 2002; or
(3) have been granted authorizations pursuant to Section 107-64 (Removal of Trees) and 107-65 and are located on a zoning lot where a change in the City Map has been approved within three years prior to February 6, 2002, and where certified copies of the alteration map for such change in the City Map have not yet been filed in accordance with Section 198, subsection (c), of the New York City Charter, as of February 6, 2002.
In order to authorize such modifications or waivers pursuant to this paragraph, (b), the Commission shall find that such zoning lots will be developed pursuant to a good site plan, and that adequate access to all dwelling units, adequate parking spaces located outside of the roadbed of the private road, adequate spacing of all curb cuts and adequate landscaping will be provided.
In R3, R4 and R5 Districts, and in C1 and C2 Districts mapped within R3, R4 and R5 Districts, and in C3 Districts, the City Planning Commission may authorize the waiver of bulk regulations for:
(a) zoning lots with private roads that access at least 20 dwelling units consisting in part of construction within streets that are unimproved and for which the Board of Standards and Appeals has granted a permit pursuant to Section 35 of the General City Law; and
(b) zoning lots with private roads that access fewer than 20 dwelling units consisting in part of construction within streets that are unimproved and for which the Board of Standards and Appeals has granted a permit pursuant to Section 35 of the General City Law and where such zoning lot has received an authorization pursuant to paragraph (a) of Section 26-26;
The Commission may authorize the waiver of bulk regulations affected by such streets where buildings would be non-complying absent such waiver, provided the Board of Standards and Appeals has prescribed conditions pursuant to Section 35 of the General City Law which require the buildings or portions thereof to be located within the unimproved streets to be compliant and conforming to the provisions of this Resolution. Such waivers shall only be as necessary to address non-compliance resulting from the location of the buildings within and outside the unimproved streets.
The Commission shall find that the private roads are adequate to serve present and future transportation needs and that, through the grant of such waivers, the development complies to the maximum extent feasible with all applicable zoning regulations as if such unimproved streets were not mapped, and that the private road system results in a good site plan.
Yards
For the purposes of this Section, a private road shall be considered to be a street, and a line seven feet from and parallel to the required curb of the private road shall be considered to be a street line, and the applicable yard regulations of Sections 23-40, inclusive, and 23-51, et seq., shall be applied accordingly. However, no yard shall be required along that side of a private road, or portion thereof, that does not have a building wall facing it. Furthermore, where a building on a through lot fronts upon a street and a private road, one front yard shall have a depth of at least 30 feet. Where such 30 foot front yard adjoins a street, such yard shall include a landscaped strip at least eight feet wide to screen the yard from such street, densely planted with evergreen shrubs at least four feet high at time of planting, and of a type expected to form a year-round dense screen at least six feet high within three years.
(a) Except in the Borough of Staten Island, the minimum distances set forth in Section 23-711 (Standard minimum distance between buildings) shall not apply between two buildings where each such building faces a front yard required pursuant to Section 26-31. In lieu thereof, such buildings shall be at least 13 feet apart.
(b) For the purposes of applying the provisions of Section 23-88 (Minimum Distance Between Lot Lines and Building Walls), the required curb of the private road shall be considered to be a street line.
The entrances and exits of all private roads shall be located not less than 50 feet from the intersection of any two street lines.
No required accessory off-street parking spaces shall be located between the required curbs of a private road, except where such spaces:
(a) are perpendicular to the roadbed;
(b) are located on only one side of a private road or portion of a private road, so that no such spaces are located on opposite sides of the road bed or within 20 feet of being opposite to one another; and
(c) are within rows of not more than 10 adjacent spaces. Such rows shall be separated one from another by a planting strip at least 18 feet deep and eight feet wide, within which a tree of at least three-inch caliper is planted.
All accessory off-street parking spaces shall comply with the parking location and curb cut regulations set forth in Section 25-632. For the purposes of applying such regulations, the private road shall be considered to be a street. In addition, the provisions of Sections 25-64 (Restrictions on Use of Open Space for Parking) and 25-66 (Screening) shall apply.
All private roads shall provide street lighting, street signage and crosswalks to minimum Department of Transportation standards for public streets.
Screening
All private roads shall be screened from adjoining zoning lots by a landscaped strip at least eight feet wide, and all open off-street parking areas with five or more spaces shall be screened from adjoining zoning lots by a landscaped strip at least four feet wide. Such landscaped strips shall be densely planted with evergreen shrubs at least four feet high at time of planting, and of a type that may be expected to form a year-round dense screen at least six feet high within three years. Such screening shall be maintained in good condition at all times.
Except in the Borough of Staten Island, the City Planning Commission may, by authorization, allow modifications to, or waivers of, the requirements of Sections 26-30 through 26-35, inclusive, provided that the depth of a rear yard shall not be less than 15 feet and the depth of a front yard shall not be less than five feet. In order to authorize such modifications or waivers, the Commission shall find that:
(a) such modifications result in a site plan that provides sufficient open areas for the residents;
(b) any reduction in open areas shall be permitted only where the Commission finds that a good site plan has been provided that includes a superior landscaping plan; and
(c) such modifications will not impair the essential character of the surrounding area.
The Commission may prescribe additional conditions and safeguards to minimize adverse effects on the character of the surrounding area.
Street Tree Planting
In accordance with applicability requirements of underlying district regulations, one street tree, pre-existing or newly planted, shall be provided for every 25 feet of street frontage of the zoning lot. Fractions equal to or greater than one-half resulting from this calculation shall be considered to be one tree.
(a) Design criteria
Street trees shall be planted along the entire length of along the curb of the street adjacent to the zoning lot, within:
(1) tree beds or connected tree beds designed in compliance with standards set forth by the Department of Parks and Recreation; or
(2) rain gardens designed in compliance with standards set forth by the Department of Environmental Protection.
For zoning lots with over 100 feet of street frontage, wherever two required street tree beds will be separated by less than 25 feet, such tree beds shall be combined and designed as a single continuous tree bed.
The species and caliper of all street trees shall be determined by the Department of Parks and Recreation, and all such trees shall be planted in accordance with the street tree planting standards of the Department of Parks and Recreation.
(b) Alternate compliance
Where such tree planting would be infeasible adjacent to the zoning lot, such trees may be provided in an alternate manner, or waived, using any combination of provisions, as appropriate, set forth in this paragraph (b).
(1) Rain gardens
Where the Department of Parks and Recreation determines that such tree planting would be infeasible, such required street tree may be substituted for a rain garden designed in compliance with standards set forth by the Department of Environmental Protection.
(2) Planters
Where the Department of Parks and Recreation or Department of Transportation determines that below-grade infrastructure causes one or more tree planting location to be infeasible, such tree may be provided in permanent planters designed in compliance with standards set forth by the Department of Transportation.
(3) Off-site locations
Where the Department of Parks and Recreation determines that such tree planting would be infeasible, or in historic districts where the Landmarks Preservation Commission determines that such tree planting would not be in character with the historic district, one or more street trees may be planted in an alternative off-site location, to be selected by the Department of Parks and Recreation, except that if the Department of Parks and Recreation determines that no alternative location is available, or if no alternative location is provided within 30 days of an application for a Department of Parks and Recreation permit, such off-site tree shall be waived. Off-site trees shall be planted at alternative locations within:
(i) an existing empty street tree pit or planting strip; or
(ii) an unpaved area owned by the City of New York.
All such alternative locations shall be within the Community District or one-half mile of such zoning lot.
(4) Payment option
Where the Department of Parks and Recreation determines that such tree planting would be infeasible, or in historic districts where the Landmarks Preservation Commission determines that such tree planting would not be in character with the historic district, in lieu of planting an off-site tree in an available alternative location, or in the event that planting adjacent to the zoning lot cannot be completed due to the season, funds equivalent to the cost of planting such tree, as established by rule of the Department of Parks and Recreation, may be deposited in an account of the City of New York. Such funds shall be dedicated to the planting of street trees by the City at an alternative location or, in the case of an off-season deposit, in front of the zoning lot at the next appropriate planting season.
Planting Strips
In accordance with applicability requirements of underlying district regulations, the owner of the development, enlargement or converted building shall provide and maintain a planting strip. Street trees required pursuant to Section 26-41 shall be planted within such planting strip. In addition to such street trees, such strip shall be fully planted with grass or groundcover, except as provided in Section 26-421. Such planting strip shall be located adjacent to, and extend along, the entire length of the curb of the street. However, in the event that both adjoining properties have planting strips adjacent to the front lot line, such planting strip may be located along the front lot line. The width of such planting strip shall be the greatest width feasible given the required minimum paved width of the sidewalk on street segments upon which the building fronts, except that no planting strip less than six inches in width shall be required.
Driveways are permitted to traverse planting strips. Planting strips may be interrupted by utilities and paved areas required for bus stops.
On zoning lots containing schools, permeable pavers or permeable pavement may be substituted for grass or ground cover, provided that, beneath such permeable pavers or pavement, there is structural soil or aggregate containing at least 25 percent pore space, or other kind of engineered system that absorbs stormwater, as acceptable to the Department of Transportation. Any area improved with permeable pavers or pavement pursuant to this paragraph shall be no less than three feet in width except where necessary for compliance with the Americans with Disabilities Act.
Applicability
This Section, inclusive, specifies ground floor level requirements that establish ground floor use and depth requirements, the maximum width for certain uses, and parking wrap and screening requirements that apply to Quality Housing buildings in certain Residence Districts subject to supplemental provisions for qualifying ground floors.
For buildings, or portions thereof, with ground floor use and depth requirements, uses on the first story of a building, and within 15 feet of the ground floor level street wall, shall be limited to community facility uses, except for lobbies, entrances and exits to accessory parking facilities, and entryways to subway stations, as applicable, provided in accordance with Section 26-53 (Maximum Width of Certain Uses). However, such minimum depth requirement may be reduced, to the minimum extent necessary, to accommodate vertical circulation cores or structural columns associated with upper stories of the building.
The maximum width of lobbies, entrances and exits to accessory off-street parking facilities, and entryways to subway stations shall be as set forth in this Section.
(a) Ground floor lobbies
Lobbies accessing uses not permitted on the ground floor level shall be permitted, provided that the width of such lobbies, in total, does not exceed 25 percent of the street wall width of the building or more than 20 linear feet of street wall frontage on a wide street or 30 linear feet on a narrow street, whichever is less. However, the width of such lobbies need not be less than 10 feet.
(b) Entrances and exits to accessory parking facilities
Entrances and exits to accessory off-street parking facilities, where permitted on the ground floor level, or portion thereof, shall not exceed a street wall width equal to the sum of five feet plus the maximum curb cut width for the applicable district. Where no specified maximum curb cut width is set forth for the district, the curb cut regulations for buildings containing residences in R6 through R8 Districts with a letter suffix, found in paragraph (e) of Section 25-631 (Location and width of curb cuts in certain districts), shall be applied.
(c) Entryways to subway stations
Entryways to subway stations may be provided on the ground floor level of a building without restriction in street wall width.
All accessory off-street parking spaces on the ground floor level of a building shall be wrapped by floor area in accordance with paragraph (a) or, where applicable, screened in accordance with applicable provisions of paragraph (b) of this Section.
(a) Along typical street wall frontages
For the ground floor level, or portions thereof, of buildings with a street wall width of 100 feet or less along a street frontage, any portion of an accessory off-street parking facility that is located above curb level, except for permitted entrances and exits, shall be located behind permitted floor area so that no portion of such facility is visible from adjacent public sidewalks or publicly accessible areas. Such floor area shall have a minimum depth of 15 feet, as measured perpendicular to the street wall of the building.
(b) Along wide street wall frontages
For portions of ground floor levels of buildings with a street wall width exceeding 100 feet along a street frontage, at least 100 feet of such frontage shall comply with the provisions of paragraph (a) of this Section. Any portion of such an accessory off-street parking facility that is located above curb level within the portion of such ground floor level street wall in excess of 100 feet, may either be wrapped by floor area in accordance with paragraph (a) of this Section, or shall be subject to the following design requirements:
(1) any non-horizontal parking deck structures shall not be visible from the exterior of the building in elevation view;
(2) opaque materials shall be located on the exterior building wall between the bottom of the floor of each parking deck and no less than three feet above such deck; and
(3) a total of at least 50 percent of such exterior building wall, or portion thereof, with adjacent parking spaces shall consist of opaque materials which may include permitted signs, graphic or sculptural art, decorative screening or latticework or living plant material.
In all districts, all energy infrastructure equipment and accessory mechanical equipment located below the rooftop level, other than solar or wind energy systems or equipment with a depth limited to 18 inches from an exterior wall, shall be subject to the following provisions when not located within a completely enclosed building, whether or not such equipment is located within a required open space, yard, or court:
- all generators and cogeneration equipment utilizing fossil fuels which are accessory to buildings other than single- or two-family residences shall be completely enclosed within a building or other structure, except as necessary for mechanical ventilation;
- all other types of equipment, including generators and cogeneration equipment serving single- or two-family residences, may be unenclosed, provided that such equipment is located at least five feet from any lot line and, where located between a street wall or prolongation thereof, and the street line, such equipment is within three feet of a street wall;
- where the area bounding all such equipment, as drawn by a rectangle from its outermost perimeter in plan view, exceeds 25 square feet, such equipment shall be screened in its entirety on all sides. Such screening may be opaque or perforated, provided that where perforated materials are provided, not more than 50 percent of the face is open; and
- where any equipment is located in a front yard, or is located within 15 feet of a zoning lot line, the equipment shall be fully screened from adjoining zoning lots, including such zoning lots situated across a street, by:
- a wall or barrier or uniformly painted fence at least as tall as the equipment it is screening, and which must be at least 6 feet, but need not exceed 15 feet in height. Such wall, barrier or fence may be opaque or perforated, provided that not more than 50 percent of the face is open; and
- a strip at least four feet wide and densely planted with vegetation that, at the time of planting are at least half as tall in height as the screen required by paragraph (1), and are of a type which may be expected to form a year-round dense screen at least six feet high within three years.
Such screening shall be maintained in good condition at all times, may be interrupted by normal entrances or exits and shall have no signs hung or attached thereto.
In all districts, all energy infrastructure equipment and accessory mechanical equipment located on roofs, other than solar energy systems, shall be subject to the following provisions when not located within a completely enclosed building, whether or not such equipment is penetrating a maximum height limit or a sky exposure plane.
All such equipment shall be screened on all sides. Such screening may be opaque or perforated, provided that where perforated materials are provided, not more than 50 percent of the face is open.