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Design Review Board

Level 2: Addition to an existing building/structure

2-B-20-DT

This case has been appealed

Staff Recommendation
APPROVE Certificate 2-B-20-DT as submitted.Case File
Location
410 W. Magnolia Ave.
Applicant Request
Installation of a parking pad, sound wall, fencing and landscaping to buffer sound and visibility of a trailer-mounted HVAC chiller proposed at the W. Magnolia Avenue and alley (AKA Conrad Street) corner of the property. The trailer-mounted chiller is needed to allow the replacement of the HVAC chiller within the AT&T building and this is the only location available on the property. AT&T may also use this as a location to store the chiller for use on other sites on an as-needed basis.

Sound wall: The sound wall will be located along the east (alley) frontage of the property to block sound to the nearby residential uses to the east. The wall will be supported by steel columns on concrete piers. The absorptive wall system is constructed with tongue and groove PVC panels that are stacked between steel columns. The wall panels will have a smooth finish and a color that closely matches the exiting brick screen wall along the alley to the south. The sound wall will abut the existing brick screen wall.

Fencing: The existing 6' tall black steel open mesh fence around the planting area and sidewalk will be partially removed to accommodate the new 6' tall screen fence and gate around the chiller. The new 6' tall screen fence will have smooth, horizontal slats with small gaps partially between the slats (see attached image).

Landscaping: One of the two existing magnolia trees needs to be removed. The remaining magnolia tree will have a barrier located at the branch drip line to protect the tree and its roots during construction. There will be five new silhouette sweetgum trees planted along the west side of the new screen fencing to provide additional screening.

Parking pad: Access to the concrete parking pad will require approximately 30' of the existing sidewalk and curb to the replaced with a reinforced concrete sidewalk and mountable curb. The road will be striped to indicate no parking in front of the gated entrance to the parking pad. No existing on-street parking spaces will be removed or modified to accommodate this project.
Staff Comments
With the adoption of the new City zoning ordinance, as of January 2020, the AT&T building is located within the review boundary of the Design Review Board. Previously, this building would not have been reviewed by the board or subject to the Downtown Design Guidelines.

AT&T is beginning the process to replace the HVAC chiller for this facility which requires the trailer-mounted chiller until the work is complete, which could take up to two years. Because of the duration of the project, the sound wall is required because the chiller will be continuously running and there are nearby residences. The sound wall has to be made of a lightweight system because it sits over buried fuel lines that cannot be easily relocated and must use as small of foundations/piers as possible.

The zoning ordinance does not permit ground-mounted mechanical equipment to be located within a front yard, which is defined as the area between the primary building and the front property line. Because this building has multiple road frontages, it was determined that the W. Depot Avenue frontage is considered the "front" because it has the main entrance to the building. The W. Magnolia Avenue frontage is considered the "rear" so the trailer-mounted chiller is permissible. The zoning regulations also require that ground-mounted mechanical equipment be "screened from public view by a decorative wall, solid fence, or year-round landscaping that is compatible with the architecture and landscaping of a development site. The wall, fence, or plantings must be of a height equal to or greater than the height of the mechanical equipment being screened." The guidelines have similar recommendations; locate mechanical equipment on non-primary facades and provide screening.

The guidelines do not address long term storage of equipment such as parking a trailer. The most similar type of use the guidelines do address is surface parking lots, which are recommended to be screened with decorative walls, fencing and landscaping. The proposal has taken this into consideration by providing the 6' tall screen fencing, retaining one mature magnolia tree, and installing five new silhouette sweetgum trees.

Applicable guidelines:

Section 1.A.3. (PARKING FACILITIES)
It is important to ensure that parking facilities (both public and private) are safe, accessible, and clearly marked. New parking facilities should be designed to be attractive, compatible additions to downtown. In general, new parking facilities should remain subordinate to the street scene.
GUIDELINES:
3c. Locate surface parking lots to the side or rear of buildings. No surface parking lots should be created in front of buildings.
3d. Screen surface lots, where they abut a public sidewalk, with decorative walls, fencing and landscaping.

Section 1.B.7. (MECHANICAL EQUIPMENT AND SERVICE UTILITIES)
Utilities can include telephone and electrical lines, ventilation systems, gas meters, air conditioners, fire protection, telecommunication and alarm systems. Adequate space for these utilities should be planned in a project from the outset and they should be designed such that their visual and noise impacts are minimized.
GUIDELINES:
7a. Minimize the visual impact of mechanical equipment through screens or recessed/low-profile equipment.
7b. Do not locate units on a primary facade.
7c. Screen rooftop vents, heating/cooling units and related utilities with parapet walls or other screens. Consider sound-buffering of the units as part of the design.
7d. Locate utility connections and service boxes on secondary walls.
7e. Reduce the visual impacts of trash storage and service areas by locating them at the rear of a building or off an alley, when possible.
Applicant

Norman / EXP

Planning Staff
Mike Reynolds
Phone: 865-215-3827
Email: mike.reynolds@knoxplanning.org
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