A building permit is required for additions such as dormers, bump-outs, sunrooms, enclosed decks or porches, bathroom additions, kitchen expansions, garage expansions, or any building addition that will expand the total square footage of the structure or add another story or expand the existing upper story.  It is also required for replacing an old addition with a new addition, even if the footprint stays the same. Proposals for additions to the principal structure require:

  • A mortgage inspection loan survey at minimum. The survey needs to be at scale.
  • A plot plan of the proposed addition drawn to scale on a copy of the survey, showing its proposed dimensions and proposed distances from front, side and rear property lines. We can help you with the plot plan when you apply.
  • Building plans including foundation plan, floor plans, cross-section showing materials and construction method, and elevations illustrating how the addition will fit into the existing structure, from several angles. You can draw the plans yourself or have your contractor draw them. They need to be understandable and reasonably to scale.
  • A completed Building Permit Application with full contact information for the property owner, applicant or agent, and contractor. 
  • The estimated cost of the project including labor and materials.  The building permit fee will be based on that cost, at a rate of $15 per $1000 estimated cost or part thereof. The minimum fee for all building permits is $25.
  • Building permit fee paid at time of application.
  • A sewer impact fee if adding one or more bedrooms. Each additional bedroom is estimated to provide the home with the capacity to use 90 additional gallons of water per day, per State of Maine regulations. Check with us for the rate per gallon per day. Application for payment of Sewer Impact Fee
  • In the case of commercial additions, a sewer impact fee may be assessed based on increased square footage, change of use, or expansion of use. Application for payment of Sewer Impact Fee

For commercial structures, any increase of 1000 square feet (including cumulative over the span of five years) will require site plan review by the Planning Board prior to applying for a building permit. Please contact the Planning Division at 207-767-7603, or email the Planning Director, Milan Nevajda, at to discuss if your expansion will trigger site plan review.  Please note that any change of business tenant in a commercial space requires a building permit and occupancy inspection, regardless of whether any tenant fitup work is being done, even in the same size space.