2.3 Measures and Exceptions

Lot Area. Lot area is measured as the total area contained within the boundary lines of a lot, excluding publicly dedicated and accepted rights-of-way.

Lot Width. Lot width is measured as the horizontal distance between side lot lines along the front lot line, with the following exceptions:

1. On a flag lot, only the flag portion of the lot is used to measure lot width.
2. On a lot accessed by an access easement, the easement is not used to measure lot width.
3. On a lot which is on a cul-de-sac or which has a curved front lot line, the setback line is used to measure lot width.

Building Coverage. Building coverage is measured by dividing the total area of building footprints of all principal and accessory structures by the total lot area, with the following exceptions:

1. On a flag lot, only the flag portion of the lot is used in the calculation of lot coverage.
2. On a lot accessed by an access easement, the easement is not used in the calculation of lot coverage.

Impervious Coverage. Impervious coverage is measured by dividing the total area of the building footprints of all principal and accessory structures and all paved surfaces of the site, by the total lot area, with the following exceptions:

1. When semi-pervious paving is used, it is calculated at a reduced percentage of impervious coverage, as follows:

   1. Pervious concrete and open grid paving systems are calculated as 50% impervious surface, provided that no barrier to infiltration is installed beneath the material. Open grid pavers must be installed on a sand base, without an impervious liner, to qualify.
   2. Other types of pervious surfaces, such as permeable pavers, porous asphalt, or gravel-crete, are credited based upon field performance data and coefficients of permeability provided by the manufacturer.

2. When a green or blue roof is installed, the area of the building that includes the green or blue roof is calculated as 50% impervious surface.

Required Yards. A required yard is the area of a lot that must be maintained clear of permanent structures, with the exception of the following permitted encroachments:

1. Accessory Structures. Accessory structures may encroach upon required yards, subject to the limitations of Section 6.2.

2. Building Features. Certain building features may encroach upon required yards, so long as they are located at least 18 inches from all lot lines and meet any additional criteria, as follows:

   1. An accessibility ramp may encroach upon any required yard to the extent necessary to perform its proper function.
   2. An air conditioner window unit may encroach a maximum of 18 inches upon any required yard.
   3. An awning or canopy may encroach up to eight feet upon any required yard.
   4. A balcony may encroach up to eight feet upon any required yard.
   5. A bay window or turret that is less than ten feet wide may encroach up to three and one-half feet upon any required yard.
   6. A building entrance that is less than ten feet wide may encroach up to three and one-half feet upon any required yard.
   7. A chimney, pre-fabricated chimney, flue, or smokestack may encroach up to four feet upon any required yard.
   8. Any ornamental lighting, lamp posts, and lawn decorations, such as benches, statues, birdbaths, and sculptures, may encroach upon any required yard.
   9. A porch or stoop may encroach up to eight feet upon any required yard, so long as it remains unenclosed.
   10. A porte-cochere may encroach upon required interior side and rear yards.
   11. A sill, belt course, cornice, eave, roof overhang, or similar architectural feature may encroach up to three feet upon any required yard.

3. Fences and Walls. Fences and walls may encroach upon required yards, subject to the limitations of Section 7.2

4. Pedestrian and Cyclist Facilities. Pedestrian or cyclist facilities, such as sidewalks, multi-use paths, and bicycle parking, may encroach upon required yards.

5. Signs. Signs, with the exception of off- premise signs, may encroach upon required yards, subject to the limitations of Article 9.

6. Utilities. Utility infrastructure located underground and structures accessory to utilities, such as hydrants, manholes, transformers, poles, transmission lines, and cabinet structures, may encroach upon required yards, except that such utility infrastructure, when located aboveground, may be located in front yards only where locating such structures in alternate locations is not practicable.

7. Vehicle Parking. Vehicle parking, including driveways and drive aisles, may encroach upon any required yard except for a required waterfront yard, subject to the limitations of Section 8.3.

Build-To Percentage. The build-to percentage specifies the percentage of the width of the building facade, measured along the adjacent right-of-way line, which must be located within a build-to zone or along a build-to line.

1. A build-to zone is an area of the lot bounded by interior side and/or corner side lot lines and two imaginary lines, which are parallel or radial to a right-of-way line and correspond to the minimum setback and maximum setback for the facade of a principal building.
2. A build-to line is an imaginary line parallel to a right-of-way line, created when the minimum setback and maximum setback for building facades are the same number.
3. The following are exceptions to the build-to percentage:
   1. An arcade, forecourt, or plaza frontage is counted as meeting the required build-to percentage.
   2. An alcove, entry door recess, or recessed upper-story balcony up a maximum of 15 feet in width is counted as meeting the required build-to percentage. In the N-1D and N-1C zones, a ground-floor lobby entrance to a tower building type may be recessed up to a maximum of one-third times the width of the facade.
   3. A chamfered corner or beveled edge of a building, designed to achieve corner visibility at a right-of-way intersection or driveway entrance, is counted as meeting the required build-to percentage, up to a maximum width as is necessary to achieve such corner visibility.
   4. Facade articulation, such as window or wall recesses or projections, is counted as meeting the required build-to percentage, so long as the variation does not exceed 18 inches of depth or projection.
   5. An outdoor dining area is counted as meeting the required build-to percentage, so long as the outdoor dining area is created by the recess of only the ground floor of the building facade, and the recess is no greater than 15’ in depth from the building facade.

Lot Depth. Lot depth is measured as the horizontal distance from the midpoint of the front lot line to the midpoint of the rear lot line of a lot, with the following exceptions:

1. On a flag lot, only the flag portion of the lot is used to measure lot depth.
2. On a lot accessed by an access easement, the easement is not used to measure lot depth.

Established Front Yard Line. The established front yard line is the mean front yard line of all principal buildings along a block face and which are located in the same zone, except as follows:

1. Where less than 25% of the combined lot widths along a block face consist of lots that are improved with principal buildings, the established front yard line will be determined by the Zoning Administrator.

2. Where one or more adjacent properties, located on the same block face as the subject property, vary from the mean front yard line by at least 10 feet, the established front yard line will be determined by the Zoning Administrator.

3. When determining the established front yard line, the Zoning Administrator must consider the following criteria:

   1. The established front yard line is consistent with the intended development pattern of the zone.
   2. The established front yard line is harmonious with adjacent development.
   3. The established front yard line allows for adequate light and air for the subject property and adjacent properties.

Building Height, Feet. When building height is measured by number of feet, building height is measured as the vertical distance from average ground level to:

1. The peak of a flat roof.
2. The peak of a gambrel or mansard roof.
3. The midpoint height between the eaves and the ridge in the case of a pitched roof (gable or hip roof).

Building Height, Stories. When building height is measured by number of stories, building height is measured as follows:

1. The first story of a structure is measured from the finished ground floor level to the surface of the second floor or, in the case of a one- story building, from the finished ground floor level to the surface of the roof. Each upper story of a structure is measured from the surface of the floor to the surface of the floor above it or, if there is no floor above, from the surface of the floor to the surface of the roof above it.
2. When building height allows for half-stories, the half-story is calculated as the space under a sloping roof where the line of intersection of roof decking and exterior wall face is no more than five feet above the top floor level.
3. When a lot slopes downward from the front lot line, additional stories are permitted in addition to the maximum number allowed

Building Height, Relative to Thoroughfare Width. When building height is determined by a ratio relative to the width of the adjacent thoroughfare, building height is measured as follows:

1. The maximum building height is measured from the average ground level to a height that equals a multiple of the total width of the adjacent thoroughfare. If a building fronts upon more than one thoroughfare, the widest thoroughfare is used to determine the height requirement. If a building fronts upon only an alley, the widest thoroughfare adjoining the block is used to determine the height requirement. If a building does not have direct frontage upon a thoroughfare, the thoroughfare to which it has required access via a permanent easement is used to determine the height requirement. If a building fronts upon a public park or navigable body of water, with or without an intermediate public right-of-way, the width of the adjacent right-of-way will be measured as 100 feet for the purpose of determining the height requirement.
2. In the N-1D zone, if the floorplate of the building is reduced so that above a given level it covers in the aggregate not more than 25% of the lot area, the building above this level may be erected to any height, provided that the distance that it steps back from the adjacent right-of-way line, plus half the width of the right-of-way, equals at least 75 feet.

Building Height Exceptions. The following are exempt from minimum and maximum building height requirements:

1. Accessory structures, which are governed by Section 6.2.
2. Chimneys, fire escapes, derricks, flues, ventilators, and smokestacks.
3. Cooling towers, grain elevators, gantry cranes, sugar refineries, gasometers, conveyors, and other structures used for a manufacturing or transshipment process.
4. Cupolas, domes, bell towers, minarets, monuments, spires, steeples, belfries, and ornamental towers, so long as they are not intended for occupancy.
5. Dining cars, locomotive cars, shipping containers, and similar structures when repurposed for permanent use and occupancy. This exception applies only to minimum height requirements; maximum height requirements still apply.
6. Bulkheads, elevator enclosures, penthouses for elevators and stairways, skylights, scenery lofts, and water tanks, so long as these structures occupy no more than 25% of the total area of the roof.
7. Green roofs, blue roofs, and other facilities used to manage stormwater.
8. Parapet walls, limited to a height of five feet.
9. Utilities.
10. Wind farms, subject to the limitations of Section 6.1.9.
11. Wireless communication towers, antennas, and ancillary structures, subject to the limitations of Section 6.1.9.

1. Story height is measured from the surface of any floor to the surface of the floor above it or, if there is no floor above, from the surface of the floor to the top of the wall plate.
2. The minimum ground floor story height must be fully met within the first 30 feet of building depth as measured from the front facade. At least 50% of the ground floor must meet the minimum story height requirement.
3. A minimum of 80% of each upper story must meet the minimum upper story height requirements.

Transparency

1. When calculating transparency for any facade, the total area of fenestration is included, as follows:
   1. Ground floor transparency is calculated based on the total facade area located between two feet and eight feet above the finished ground floor level.
   2. Upper floor transparency is calculated based on the total facade area located between the surface of any floor to the surface of the floor above it or, if there is no floor above, from the surface of the floor to the top of the wall plate.
2. For any windows to be included in the transparency calculation, the glazing must meet the following criteria:
   1. For ground floor glazing, the glazing must have a minimum 60% Visible Light Transmittance (VLT) and no more than 15% Visible Light Reflectance (VLR). The ground floor glazing must remain unobstructed up to a minimum depth of five feet, with the exception of obstructions, such as window signs or product displays, that do not take up more than 25% of the total window area.
   2. For upper floor glazing, the glazing must have a minimum of 40% VLT and no more than 15% VLR.

Ground Floor Blank Wall Width. Ground floor blank wall width is measured as any linear dimension of contiguous building wall on the ground floor that does not contain fenestration.

Ground Floor Window Sill Height. The ground floor window sill height is measured from the base of the building immediately beneath the window sill to the point where the window sill glazing commences.

Main Entrance. A main entrance is a principal point of access for pedestrians into a building, prominently visible from the adjacent right-of-way or avenue of approach. To be considered a main entrance, a door must be open to and operable by the general public, for both entering and exiting, during business hours in the case of a non-residential use, or operable at any time by occupants in the case of a residential use. An emergency exit or service entrance is not considered a main entrance.

Entrance Spacing. Entrance spacing is measured as the linear distance between the edges of doors along the facade.