ADU Rules in Kingston, NY: What the City Code Says and How to Start

By Spenser McCoy

If you own a home in the City of Kingston, you may be able to add an accessory dwelling unit, or ADU: a separate small home on the same lot, either attached to the house or in a detached, backyard building. Kingston updated its zoning in 2023, so older articles may be out of date. Here is what the current city code says, and what you should confirm for your own lot. This is general information only.

THE CODE THAT APPLIES

Kingston adopted a new Chapter 405, the Kingston Form Based Code, in August 2023, replacing its earlier zoning rules. Instead of sorting land only by use, it sorts the city into "transect" zones such as T3, T4 and T5 that describe how built-up a neighborhood is. Your zone, shown on the city's regulating map, drives most of what you can do. Old proposals from 2021 for a city ADU law were drafts, not today's rules.

WHAT THE CODE SAYS ABOUT ADUs

The code defines an ADU as a unit independent of the primary home, and it can be attached or detached. Its tables list ADUs as permitted in most residential zones, but the table is dense, so confirm your zone.

For a detached house or a duplex, the code allows one ADU per lot. Up to two may be allowed through a "major waiver," which is a Planning Board decision. A rear "carriage house" building can hold one ADU. The code limits that building to about 36 feet wide by 30 feet deep and requires 10 feet of separation from the main building.

Accessory buildings are limited to 2.5 stories. Accessory-building setbacks vary by zone. In several zones the rear setback is as small as 3 feet and the side setback 3 to 5 feet.

LOT COVERAGE IS OFTEN THE REAL LIMIT

Lot coverage counts buildings plus driveways, patios and parking. The maximum is 70% in T4N, 50% in T3N, 30% in T3L and 25% in T2C. On many lots, coverage runs out before setbacks do, which is why a survey matters before you get attached to a plan.

PARKING

Residential parking in several zones is set as a maximum, not a minimum, so you are generally not required to add spaces. The city amended its parking and short-term rental sections in July 2025, so confirm current rules.

WHO REVIEWS WHAT

A building permit comes through the city's Building Safety Officer. Minor waivers are decided by the Planning Administrator. Major waivers go to the Planning Board. If your property is in a historic or landmark district, expect an additional review before a permit. Whether a detached ADU needs site plan review turns on code wording we have not been able to confirm.

FUNDING

The City of Kingston appears on Ulster County's list of municipalities for the Plus One ADU grant program run with RUPCO. Grant rules, income limits and availability change; confirm directly with RUPCO.

WHERE ONEBUILD HELPS

We are a designer-led coordination firm. We read your lot's zone, the code sections and the review path, and we help you line up the questions before you commit to design or construction spend. We coordinate; you contract directly with the builder and the manufacturer.

Book a free 30-minute Discovery Call to talk through your Kingston property.

Confirm all rules with the City of Kingston. Informational only; not legal or permitting advice.

ANSWERS TO QUESTIONS YOU MAY STILL BE ASKING

Q: Are ADUs allowed in the City of Kingston, NY?

A: The city's Form Based Code defines ADUs and lists them as permitted in most residential zones, subject to the rules for your zone. Confirm with the city.

Q: How many ADUs can I have on one lot in Kingston?

A: For a detached house or duplex, the code allows one ADU per lot, with up to two possible through a major waiver reviewed by the Planning Board.

Q: Do I need to add parking for an ADU in Kingston?

A: Residential parking in several zones is a maximum rather than a minimum, but rules were amended in 2025, so confirm with the city.

Q: Who approves an ADU in Kingston?

A: Building permits go through the Building Safety Officer; waivers go to the Planning Administrator or Planning Board. Historic districts add review.

Q: Is the Town of Kingston the same as the City?

A: No. They are separate municipalities with separate codes.