Historic Zoning Commission

Old North Knoxville H: Level II

3-J-21-HZ

Applicant Request

Proposed new accessory structure (accessory dwelling unit) to be located behind the primary residence. Overall form and design was reviewed and approved with conditions by the HZC in November 2020. Due to the completion of a survey and site plan constraints; applicant is proposing the rotation of the previously reviewed structure by ninety degrees, with the garage door now facing the alley. Previously approved structure measured 30' wide by 21' deep; new structure to measure 28' wide by 22.5' deep. Structure to be placed to the rear of the primary residence, set 10' from the rear lot line and 5' from the interior side lot line.

Accessory dwelling unit to feature a 9/12 gable roof clad in asphalt shingles, with the front gable fields aligned with the alley (garage elevation) and the primary residence. 3/12 shed-roof dormers are centered on each roof slope, featuring 1/1 double hung wood windows (32" wide over 48" tall, centered over lower windows).

Revisions also include smaller windows on the first story; all windows on the first floor are proposed to be 36" by 36". New design also includes a door on the leftmost bay of the west elevation.

As previously reviewed and approved, the shed will rest on a concrete slab foundation and be clad in fiber cement (Hardie Plank) lap siding.

Applicant is also requesting a modification to the previously issued COA, which included the condition that the gable fields be clad in shingle siding, to connect the structure with the primary residence. The applicant is proposing painted lap siding instead of previously requested shingles.

Site Info

One-story frame with hipped roof with cross gables. Wood weatherboard wallcovering. Asphalt shingle roof covering and wood shingles in gable ends. Double-hung one-over-one windows with cottage window on front façade. One-story one-half front porch with turned wood posts. Two interior offset brick chimneys. Brick foundation. Irregular plan. Projecting bay on north elevation.

1. 401 E. Oklahoma Avenue is a contributing resource to the Old North Knoxville Historic District and local overlay. The overall footprint, massing, and general design and proportions of the proposed accessory structure were reviewed and approved with conditions by the HZC in November 2020 (10-K-20-HZ).

2. The new application proposes rotating the new structure 90 degrees, orienting the garage door towards the alley, and modifying the footprint slightly (from 30' wide by 21' deep to 28' wide by 22.5' deep). The structure will still be located to the rear of the primary residence, 10' from the rear lot line and 5' from the interior side lot line. Per City Zoning ordinance (10.3.P.2.a), when a detached garage is served by an alley, the minimum required setback from the rear lot line is 12' when garage doors are oriented to the alley.

3. Rotating the structure 90 degrees from the previous approval does not significantly modify the proposed structure's effect on the primary residence or neighborhood context.

4. Shrinking the first-story windows to 36" by 36" makes them disproportionately smaller than the dormer and gable windows on the second story, and create larger expanses of blank walls. In staff's opinion, the previously-reviewed window sizes should remain in the new design.

5. The west elevation now includes a door on the left side instead of centered on the elevation. The header height of the door should be aligned with the windows' header height.

6. Previous discussions focused on the structure's overall massing, height in relation to the primary structure (not modified from previous approval), and how to best connect the structure with the primary residence on the lot. The condition of approval identified in November 2020 was to include shingles in the gable fields to match the shingles on the primary residence. This design tactic was intended to break up the large massings and connect the outbuilding with the primary residence.

Fiber cement board (HardiePlank) was approved as the structure's siding material; HardiePlank shingles are applied as swaths of siding instead of individually cut shingles. Fiber cement shingles are significantly more thin than wood shingles and the "random width" product does not sufficiently reflect the depth and detail of sawn wood shingles. In staff's opinion, the applicant should either install shingles cut specifically to match the main house, or use a painted lap siding with a horizontal trim piece separating the gable field from the first story.