12.64.501 Building Height Massing Regulations

12.64.501 Building Height Massing Regulations.

The objective of this section is to ensure that all new or renovated downtown buildings have a well-formed “base” and top.” A building base provides form and definition to the pedestrian-scale public room of its adjacent downtown street spaces. A building’s top or cap contributes to a distinctive skyline and overall massing of the downtown, whether seen immediately looking up from the street below or at a distance from another part of the city. The requirements that follow outline minimal measures to compose the vertical mass of building façades. The application of architectural elements and architectural style such as (but not limited to) those respectively outlined in BMC 12.64.503 Architectural Elements, 12.64. Architectural Styles, and 12.64.505 Historic Resources Guidelines are strongly recommended to create well-integrated and attractive architecture.

A. Street & River Façade Height Massing Elements

1. Base Element. As conceptually depicted in the accompanying diagram, a horizontal articulation of street and river façades shall be applied within the first floor (or in the case of buildings above four stories, optionally within the second floor as well), to form a horizontal “base” of the façade at the building scale. A secondary lower base treatment shall be provided at the pedestrian scale (i.e. within the height of the ground floor, relating to the height of the human body). These treatments strongly define the pedestrian-scale space of the street or riverfront and shall be well-integrated into the overall façade composition. See BMC 12.64.503(A)(2) Building Base for additional guidelines outlining recommended Building Base design.

2. Top Element. A substantial horizontal articulation of street and river façades shall be applied at the top of the uppermost floor of the façade, to result in a termination of the façade that provides an attractive façade skyline and a completion of the upper façade composition. This “cap” shall be architecturally integrated with any sloping roof volume (if used) that occurs above the eave line.

1. Full Requirements. Requirements for Side and Rear Façades are the same as those for Street Façades in the following cases:

a. Where building wall to building wall clearance is more than 10 feet.

b. Where a side or rear yard of greater than five feet exists and the adjacent property has no building volume providing horizontal obstruction.

c. Where the side or rear wall faces upon a public open space or active open space such as a plaza or courtyard.

2. Flush Treatments Permitted. The minimum requirement for Height Massing Elements may be satisfied by flush wall height massing treatments where building wall to building wall clearance is more than five feet and no greater than 10 feet. Flush wall height massing treatments shall consist of one or more of the following elements which match vertical increments used on the street or river façade(s) of the building:

a. Integral color change between increment of base and portion of wall above, and/or between increment of top element and portion of wall below.

b. Horizontal score lines matching top, bottom, and/or other lines of street façade horizontal articulation.

c. Horizontal façade recess(es) matching top, bottom, and/or other lines of street façade massing elements.

3. No Requirements. No Side or Rear Façade Height Massing is required where building wall to building wall clearance is five feet or smaller.

C. Height Massing Element Guidelines. The following are examples of top element types that may be used to satisfy the required street façade height massing requirement:

Note: Fabric awnings are not counted towards a required height massing element.

1. Cornice. A Cornice may be applied as the top of street façade or a building base as a built-up material articulation that steps forward from the façade plane into the right-of-way or required setback. This step provides a significant opportunity for shadow lines and façade delineation; to this end, a minimum of three cornice “steps” or layers should be used. This element can be used on a façade independently or can be located atop a series of pilasters which are placed at regular intervals (usually to dictate bay width).

2. Canopy. A Canopy element serves as an intermediate or final height massing element or “lid” at a ground floor façade, or as a street façade cap. Its purpose is to provide shade or cover for pedestrians or sidewalk dining and/or to establish a strong horizontal massing element and “shadowline” in the façade. It can be a continuous horizontal element, a series of repeated elements (typically above shopfront windows), or a single “feature” element occurring at a structure’s main or secondary entrance. A Canopy and its related building components should be constructed of an accent building material (such as metal, tempered glass, or roof material used elsewhere on building) that is compatible with the primary building material.

3. Shaped Parapet. A Shaped Parapet is the freestanding upper extension of the street façade extending above the point where the roof intersects behind it. A Shaped Parapet provides visual completion to the top of a building façade and develops a distinct and recognizable skyline for the building. The form of a Shaped Parapet may be unrelated to the roof form behind it. In many cases, the form of a shaped parapet has traditionally been symmetrical. Generally, Shaped Parapets and their related components should be constructed of the primary wall cladding (such as brick, stone, or stucco) or an accent building material (such as wood or metal) that is compatible with the façade composition.

4. Façade Offset. A Façade Offset is a horizontal plane break where a portion of the façade steps back a sufficient distance in order to break the building into smaller volumes. Generally, a Façade Offset (recess line) applies a Cornice, Canopy, or Shaped Parapet along the edge of the offset to add visual interest and appropriately define the resulting building volume. Use of this element satisfies BMC 12.64.203 Special Height Regulations.