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Height Recommendations. September 25, 2008 Zoning Commission Case No. 08-06-01 The District of Columbia Office of Planning’s Comprehensive Review of Zoning Regulations. Height Regulation Background. 1910 Height Act Height measured by width of street District Zoning Regulations:
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Height Recommendations September 25, 2008 Zoning Commission Case No. 08-06-01 The District of Columbia Office of Planning’s Comprehensive Review of Zoning Regulations September 25, 2008
Height Regulation Background • 1910 Height Act • Height measured by width of street • District Zoning Regulations: • Height measured by zone • May be more restrictive than Height Act • Both documents are interpreted by the Zoning Administrator September 25, 2008
Height Topic Area Review Process • Working Group • Taskforce • Public Review • Zoning Commission September 25, 2008
GOALS OF HEIGHT REGULATION PROPOSALS • Make Consideration of Height in Zoning Regulations Clearer and More Predictable • Acknowledge Ambiguities in Regulation of Height • Resolve Potential Differences by Balancing: • Previous Interpretations and Precedent • National Symbolism of Skyline and Tradition of Horizontality • Physical Factors • Sustainability Considerations • Impact on Development Potential September 25, 2008
Major Topics Considered • Determining a Building’s Maximum Permitted Height • Measuring a Building’s Height • Understanding the Types and Heights of Structures Permitted Above a Roof September 25, 2008
Topics Not Considered HERE • Appropriate Heights for Particular Zones or Locations • Whether the Height Act Should be Changed September 25, 2008
Recommendations • DETERMINING MAXIMUM PERMITTED HEIGHT Rec. 1: Streets with multiple frontages Rec. 2: Streets fronting on open space Rec. 3: Business vs. Residence streets Rec. 4: Single vs. Multiple Buildings B. MEASURING A BUILDING’S HEIGHT Rec. 5: Location of Bottom Measuring Point Rec. 6: Elevation of Bottom Measuring Point Rec. 7: Natural Grade Rec. 8: Top Measuring Point C. STRUCTURES ABOVE A ROOF Rec. 9: Structures Permitted Atop a Roof Rec. 10: Height, Width, Massing Rec. 11: Roof Structure Setbacks Rec. 12: Exterior Walls September 25, 2008
Rec. 1:Frontage on Multiple Streets • Any street abutting a building’s property line may be used to determine the maximum height. • There should be no requirement for the presence of an door or entrance. • Consistent with current practice. Clarifies that a building may draw height from any side regardless of the presence of a door.
Rec. 2: Buildings Confronting Federal Reservations or Open Space Clarify what R-O-W may be used to determine height May use “A”, “B”, “C” or “D” but not “E” or “F” May not add two R-O-W or include reservation 10
Rec. 2: Potentially Affected Federal Reservations or Open Space 11
Rec. 3: Residence & Business Streets • A “Residence street” would be a) any block face that contains any residential property located in a low to moderate density zone district; or b) any block face entirely made up of properties of any existing residential zone. • A “Business street” would mean any other block face. As with Recommendation 1, a property adjacent to both a commercial and a residence street could choose its frontage. 12
Rec. 4: Single Building or Multiple Buildings? • Existing regulations: • do not recognize connections below ground • imply connections must be above ground • provide no definition of above ground connection • There is little consistency in existing practice • Applicant burdened with proving undefined “meaningful connection” 15
OP Recommends: Distinction between single & multiple buildings needs to be clarified To be considered single, a building must have The presence of an enclosed connection that permits passage by building users on at least one floor And/or Common usable space accessible by all occupants of the building Rec. 4: Single Building or Multiple Buildings? 16
Rec. 5: Location of Bottom Measuring Point Clarify the location of the measuring point for building height when a building faces more than one street. 17
Rec. 5: Bottom Measuring Point Option 1: The street chosen to determine the maximum allowable height must also be used to determine the point from which building height is measured. • New approach that ensures that height on at least one frontage is based on street width • Could decrease amount of square footage developable on through block sites with significant elevation changes • Potentially makes dozens of downtown buildings non-conforming 18
Rec. 5: Bottom Measuring Point Option 2: Any abutting street may be used to determine the measuring point regardless of which street is used to determine maximum allowable height. • Follows over 50 years of precedent • Would not affect existing or planned projects • Preserves existing development potential within the Height Act 19
Rec. 6: Elevation of Bottom Measuring Point OP Recommends: • Measure from the front of the building based on the elevation of the curb plus a slope for drainage. • Height Act says sidewalk • Zoning Regulations say curb 20
Rec. 7: Natural Grade • Clarify definition of natural grade and measuring point for elevated or depressed areas • Natural grade is the ground elevation prior to issuance of first permit needed for new building construction. • Where street frontage is affected by an artificial elevation, height is measured from the logical continuation of the surrounding street grid 21
Rec. 8: Top Measuring Point • Buildings shall be measured to the top of the roof including any parapet on exterior walls, or any other continuation of the exterior walls. • Buildings below the Height Act may add a 4’ parapet 22
Rec. 9: Structures Permitted Atop a Roof Organize and modernize the list of structures allowed on the roof. • Ornamental features limited to spires, towers, domes, pinnacles, and minarets, that are aesthetic, primarily vertical elements of a building, even if used to cover/hide/mask utilitarian or amenity features; 23
Rec. 9: Structures Permitted Atop a Roof Organize and modernize the list of structures allowed on the roof. • Utilitarian features including, but not limited to, mechanical equipment, safety railings, stairwell access, elevator penthouses, and building components or appurtenances dedicated to the environmental sustainability of the building; and Utilitarian Ornamental Utilitarian 24
Rec. 9: Structures Permitted Atop a Roof Organize and modernize the list of structures allowed on the roof. • Amenity features such as structures accessory to communal outdoor recreation space, communal pergolas, communal enclosed recreation space, and structures limited to providing individual unit access to private, unenclosed space atop a roof. 25
Rec. 10: Height, Width and Massing of Structures Atop a Roof • Remove roof structures from FAR calculation and allowed to occupy up to 40% of roof area • Remove uniform height & single enclosure requirements • Utilitarian and amenity features may not rise more than 20’ above the roof • Ornamental features: • 30’ limit • may contain utilitarian or amenity features • Special Exception relief allowed for all of these requirements 26
Rec. 11: Setbacks for Structures Atop a Roof • Utilitarian and amenity features shall be set back 1 to 1 from: • exterior wall (Rec. 12); (b) wall set back from and facing a side lot line; (c) lot line wall when taller than adjacent building Special Exception relief allowed for these requirements Additional Study is needed for setbacks atop rowhouses and single family homes 27
Rec. 11: Setbacks Atop a Roof A C B 28
Rec. 12: Exterior Walls An exterior wall is anywall facing a public street or alley • Decades of precedent have not considered alley facing walls to be exterior walls. • Recommendation would not consider party walls or other side walls to be exterior walls • BZA would not be able to grant setback relief from exterior walls above level of Height Act. 29
Next Steps • Public Comments • Guidance from Zoning Commission • Drafting Proposed Zoning Text • Further Public Comment & Commission Consideration September 25, 2008