Plainfield, NJ Building Setbacks & Zoning: Lot Coverage Limits (2026)

Section 17:9-20 sets the coverage ceiling for assisted living facilities in the City of Plainfield: a maximum permitted building coverage of forty percent (40%) and a maximum permitted total lot coverage of fifty percent (50%). The two figures measure different things. The Land Use Ordinance defines building coverage as the ratio of the horizontal area, measured from the exterior surface of the exterior walls of the ground floor of all principal and accessory buildings on a lot, to the total lot area. Lot coverage is the portion of a lot covered by structures and buildings, paved surfaces, and patios, except decks and above ground swimming pools. Impervious coverage is any material or structure, including gravel, concrete and asphalt, that prevents or restricts absorption of stormwater into the ground.

The cap comes with lot and yard rules in the same section: a minimum lot area of two (2) acres, a front yard setback of fifty (50) feet, a side yard of thirty (30) feet, a rear yard of fifty (50) feet, a buffer at least twenty (20) feet wide of massed evergreen and deciduous plantings next to a residential use, and a maximum building height of forty (40) feet or three (3) stories, whichever is less. A Certificate of Need from the New Jersey Department of Health and Senior Services is also required.

Senior centers carry higher ceilings under § 17:9-49A: Maximum Percent Building Cover 75% and Maximum Percent Total Lot Cover 90%, on a minimum lot area of 1 acre. Accessory structures use a different yardstick under § 17:9-19(D): 35 percent of the principal structure's ground area in residential zones and 40 percent in nonresidential zones. Zone-by-zone bulk numbers for ordinary lots are referred to Schedule B, an attachment to Chapter 17, and are not reproduced in the code text this page quotes, so none are stated here.