To build virtually anything you will need to secure several permits from the local government, local utilities, and the state. Always assume you need a permit unless the permitting agency has told you in writing that you don’t. Do not assume that your general contractor will know which permits need to be secured prior to construction. 

Permits cover a wide range of your needs, from construction permits, to electrical permits, to water/wastewater permits, to even environmental permits if your ADU is near a wetland or other sensitive habitat. Whether or not you are acting as your own general contractor, one of your first steps should be to consult your town’s zoning map (see HOW TO READ A ZONING BYLAW). This should give you a good indication of any special restrictions that may apply to your property. You will likely need to secure a zoning, or “development,” permit if your town has a zoning code.

Permits need to be submitted in a rough sequential order before construction can commence. Things to consider:

  • First, the floodplain and septic permits need to be approved if you are in a floodplain and looking to add your ADU to a septic system. (Check the FEMA Flood Map Service Center)
  • If you are not adding your ADU to a septic system and are instead adding it to a municipal sewer, then there will be a permit you must submit. There will be a separate permit if you are connecting to municipal drinking water supply. Contact your town office for more information on connecting to municipal water and sewer.
  • To establish new electric and/or gas service, you will need to contact your local utility provider.
  • Finally, the building permit. Bear in mind that all rental units, including ADUs, are subject to VT state building permits. In all likelihood, you will also need to apply for a local building permit. Check with your local jurisdiction for details.

Lastly, be wary of your timeline and budget for this step. Each permitting office or Zoning Board of Adjustment will have a different advertised timeframe and application fee for reviewing your permit applications. Permits may cost as much as 1% of construction costs. A good rule of thumb is each permit will likely take about a month to review.


New Hampshire

See HOW TO READ A ZONING BYLAW to find out how zoning regulations may affect your project.