§ 5.2.5. Height measurement requirements and thresholds.

A.

Building height of all structures other than single-family detached dwellings shall be measured from average finished grade (determined by averaging the elevations of finished grade around the entire footprint of the structure) to the top of the highest roof beams on a flat roof, to the deck level on a mansard roof, and to the average distance between the eaves and the ridge level for gable, hip, shed and gambrel roofs.

B.

Building height for single-family detached dwellings shall be measured from the front-door threshold of the structure to the highest point of the roof of the structure. Threshold means the top of the subfloor in the opening that is designated as the front door of a dwelling.

C.

Building height for buildings located within Residential Infill Overlay Districts shall meet the standards established in the overlay district regulations of article 3.

D.

Elevation of single-family detached dwelling thresholds. The following standards shall apply to single-family detached dwellings that are not located in a Residential Infill Overlay District:

1.

Replacement of a single-family detached dwelling. If new construction of a single-family detached dwelling would require alteration or eradication of the threshold of a previously existing residential structure, the proposed front door threshold elevation for the new single-family detached dwelling shall not be more than two (2) feet higher than the front door threshold elevation of the previously existing residential structure, which shall be measured and certified by a licensed surveyor or engineer.

2.

Construction on vacant or undeveloped lot. If no dwelling previously existed on the lot, the threshold shall be no higher than the average elevation of the existing natural grade at the front building line.

3.

Sewer conditions. If the existing residence or lot is not connected to county sewer and if an applicant for a building permit establishes that the minimum threshold height prevents gravity flow connections to county sewer, the director of planning, upon the recommendation of the watershed management director or designee, may grant an administrative variance to allow the threshold height to be up to five (5) feet above the threshold of the previously existing residence in order to allow for gravity flow into the existing sewer tap. Should a greater increase in threshold height be required, a variance from the zoning board of appeals must be obtained in accordance with the process set forth in article 7.

4.

Topographical conditions. If exceptional topographical restrictions exist on the subject lot that were not created by the owner or applicant, then the director of planning may grant an administrative variance to allow the threshold to be up to three (3) feet above the threshold of the previously existing house.

Building Height Measurement

E.

Height requirements.

1.

The maximum height of a new single-family detached dwelling shall comply with the requirements of Table 2.2.

2.

Except in the Airport Compatible Use Overlay District, the height limitations established in this chapter shall not apply to the following:

a.

Barns, silos or other similar structures when located on farms; belfries, steeples, cupolas and domes; chimneys; and flagpoles.

b.

Bulkheads, elevator penthouses, rooftop mechanical equipment, water tanks and scenery lofts and similar structures, provided that these structures shall not cover more than twenty-five (25) percent of the total roof area of the building on which the structures are located.

c.

Telecommunications towers and antennas otherwise permitted by this chapter by special administrative permit or permitted by special land use permit by the board of commissioners pursuant to section 4.2.56.

d.

Any single-family detached dwelling that exceeds the building height limitations set forth in subsection (a) and has been damaged by fire or other act of nature may be reconstructed to its verifiable original height.

e.

When an undeveloped single-family lot is located within a platted subdivision in which at least sixty (60) percent of the lots have had certificates of occupancy issued for single-family detached homes that exceed the building height limitations set forth in subsection (1) above, a single-family detached residential structure built on the undeveloped single-family lot may be built to a maximum height equal to the average building height of the existing single-family detached homes within the same block in which the undeveloped single-family lot is located.

f.

Rooftop mechanical equipment, vent pipes, lightning rods, solar panels, and/or wind vanes that are less than six (6) feet in height measured from top of roof adjacent to such structure.

( Ord. No. 15-06 , 8-25-2015)