First, you have to know if town has zoning. Not all towns have zoning bylaws. If they do, you should be able to find the bylaws on the town website. But, then how do you read the thing?

An easy way to understand any local zoning and what you will need for a permit is to talk with the town’s Zoning Administrator (that position may have a different title depending on the town.)

If you want to do some homework ahead of time, look on the zoning map which depicts the boundaries of each zone or district, and find your property on the map. Each district has its own regulations about what can be built there and how. In most towns, an accessory dwelling unit just requires a permit. You file an application, pay a fee, and your permit is issued within a month. Then there is a short appeal period to wait out, and then you can build.

As you consider what you might build and how, look at the district standards. These dictate the minimum and maximum permitted sizes of structures, where those structures can be located on your lot, and the minimum lot size required to build a given structure. Here is a generic list of standards you should be aware of when planning a project:

  • Minimum lot size: The smallest lot area required to build a new structure.
  • Setback: The required buffer distance between your structure and your front, rear, and side property lines. Pay attention to how this is measured, since it may include decks and anything else that sticks out of the building. Don’t just think of the foundation. Also, many older lots have poorly defined boundaries, so check your deed and what your neighbors think are the lot lines.
  • Height requirements.
  • Parking.
  • Steep slope restrictions: The maximum grade (i.e. steepness) of land you are allowed to build on.
  • Lot coverage limits: More common in urban or downtown settings, this dictates the maximum footprint a building may take up on a given lot.

The laws in NH and VT around ADUs have changed recently and some older bylaws will not have been updated. New state law is effective regardless. Once you get a good idea of what you think you can do, check with the Zoning Administrator again. It may help to draw a crude map of your lot.

And remember, the zoning permit is probably not the only permit you need. See the Permitting page for more details.

Next, the CONSTRUCTION phase.