ADU Rules in Germantown, NY: What the Zoning Law Says and Where to Start

By Spenser McCoy

If you own a house in Germantown and are thinking about a small second home for a parent, a grown child or a long-term tenant, the Town's zoning law already has a category for it. Germantown calls it an accessory apartment. The rules are based on your zoning district, your lot size and your septic or sewer service, so this guide is a map of the questions to settle first, not a ruling on your property. Note one thing up front: the Town has been working on a full rewrite of its zoning law, so the details below could change.

What the 2022 zoning law says

The version of the Zoning and Subdivision Law posted on the Town's website (the 2022 edition) allows one accessory apartment per single-family dwelling, up to 800 square feet. It can sit in an accessory structure, such as a detached cottage or a garage, or inside the main house. An apartment in a garage attached to the house by a breezeway is treated as an accessory apartment rather than a two-family dwelling. The apartment does not count as an additional residential unit when the Town calculates density.

The permit type and the board

The law's use table lists the accessory apartment as a special permit use, and the law says special use permits are issued by the Planning Board.

Lot size and septic

The lot has to meet the minimum acreage for its district, unless it is part of a major subdivision approved after the law took effect. The minimums in the law range from 10 acres in the NR district and 3 acres in AR, to 2 acres in RR, to as little as 5,000 to 7,500 square feet (plus an allowance per dwelling unit) in the hamlet districts when public sewer is available. Without public sewer, those hamlet districts require one acre. The law also says no permit of any kind will be granted for an accessory apartment without adequate septic or sewer service. For many properties, that sentence decides the project, so find out what you have before you design anything.

What to check before you design

1. Your zoning district, from the Town's zoning map.

2. Whether your lot meets the minimum acreage for that district.

3. Whether you are on public sewer or a private septic system, and the age and capacity of that system.

4. Whether the Town would treat your plan as an accessory apartment or an elder cottage.

5. Where the unit could sit under the setbacks that apply to accessory structures.

Where OneBuild helps

OneBuild is a designer-led coordination firm. We are not a general contractor, so you contract directly with the builder and manufacturer. We take no commission from manufacturers or contractors. A feasibility study reads the code for your parcel and checks zoning, setbacks, septic or sewer, and utilities before you commit to design or construction spend, including the advice that a site should not be built on. We cannot promise a permit, an approval or a schedule, because the Town decides those.

Next step

Book a free 30-minute discovery call. Bring your address and a short description of who the unit is for.

Informational only. This is not legal advice. Zoning laws are being revised and apply parcel by parcel, so confirm everything with the Town of Germantown.