Historic Zoning Commission

Fourth and Gill H-1: Level II

3-J-20-HZ

Staff Recommendation

Staff recommends approval of the work as proposed, with the condition that the panels receive non-reflective coating (if possible) to minimize visibility from Gratz Street.


Location Knoxville
831 Deery St. 37917

Owner
Marian Marian Sing

Applicant Request
Level II. Major repair or replacement of materials or architectural elements
Skylights/Solar
Proposed installation of solar panels on the southwest roof slope of the house. Solar panels will be one array of eight panels, two panels wide by four panels long. Panels are proposed to be installed on a low-slope roof on the southwest corner of the house (the house's rear left corner). Panels are approximately 66" long by 39" wide by 1.38" tall and will be attached to the roof via a metal racking. Solar contractor has stated that metal racking will be between 1.3" to 3" tall, depending on the job. At maximum, the panels would project 4.38" above the roof slope.

Inverter and meter to be installed adjacent to current utility box near the house's rear entry on the west elevation.

Condition approved at 3/19/20 HZC meeting: panels to receive non-reflective coating, if possible, to reduce visibility and sheen from public right-of-way.

Staff Comments
Queen Anne, c.1900
    One story frame with vertical grooved wooden sheet siding (T-111). Hip roof with lower cross gables and asphalt shingle roof covering, diamond shaped attic vents. Two over two double hung replacement windows with one over one double hung tripartite window on gabled pediment on front elevation. One story front porch with replacement wood columns, and one original chamfered wood post on a weatherboarded truncated pier. Interior offset brick chimney. Added exterior side brick chimney filling one side of projecting bay window. Brick foundation. Irregular plan. Chimney on south elevation projecting bay has a cast head of Robert E. Lee on a plaque, in bas relief, facing south.

Roofs
5. Do not use solar collectors, modern skylights, or inappropriate structures on roof planes that are visible from the street. Do not install them where they interfere with decorative roof elements. If they are installed, they should not comprise more than 3% of the total roof surface.

Mechanical Systems
3. If used, solar collectors should not be visible from public streets.

PROPOSED SOLAR PANEL GUIDELINES FOR FOURTH & GILL (see Comments):
Contemporary solar additions to building roofs have no historic counterpart and make a strong impact of the visual character of existing buildings. While both goals of historic preservation and energy conservation are important, care must be taken that one is not achieved at the expense of the other.

In designing and obtaining permission to install solar technology on a historic home, applicant is to consider the following preferences and requirements for design and placement of solar devices. These provisions are designed to minimize irreversible visual and structural impact of the devices on the historic appearance of the building.

Historic Zoning Commission is under no obligation to approve projects that do not adhere strictly to these guidelines, and may require that more preferred alternatives be pursued as a condition of project approval.

Requirements:

Solar technology should not be visible from public streets or, if visible, should be installed on an accessory building, a rear facing elevation, or a side elevation that does not face onto a public street.

Exception:
In the event that street-facing elevations are the only reasonable placement possible, the solar installation should be non-reflective and fully integrated with the building envelope or cladding.

In all cases, regardless of the location of the solar installation -

1. Solar collectors and mounting systems should be compatible in color to the property's roof materials.

2. Framing equipment associated with the installation of solar technology, including brackets, edging around solar collectors, and other metal features, should be treated, color clad, or covered to be made as unobtrusive as possible and to minimize contrast between the solar collectors and equipment and any roofing materials.

3. Slope, elevation and position relative to existing architectural features should be minimally visible from public streets.

4. Historic roofing materials or features, including dormers and chimneys, may not be irrevocably altered or removed for the solar installation.

6. For roof-mounted solar installations:
a. On a sloped roof:
The solar equipment should be mounted parallel to the roof slope and not more than six inches above the roof, as measured vertically from the top of the equipment to the roof surface. With the provided exception of building-integrated solar technologies, solar equipment should not be located forward of any point of a roof slope facing a public street or closer than 1/3 the depth of the main body of the roof if there is no slope toward the street (see diagrams)

b. On a flat roof:
The equipment should be set back from the roof edge, and visibility from ground level should be minimal.

Case History