Anything over 5 feet by 5 feet is considered a structure and will require a building permit. If electricity or plumbing is going to be within the structure you will also need those separate individual permits.
Are you proposing a shed or accessory structure that is larger than 14 feet by 24 feet? If so, please contact the Building Department for additional information at 508-699-0100 ext 2527.
If your accessory structure is smaller than 14 feet by 24 feet you will need to know your zoning district to figure out what your setbacks for the area are.
Now that you know your zoning district you need to find the mandated setback requirements for the area. Please note that IF you are on a corner lot (even frontage on a paper street equates to being on a corner lot) you will have to accommodate for 2 - front yard setbacks.
If your accessory structure is under 200 square feet in area and less than 12 feet tall then you may be able to locate your accessory structure half the distance to your side and rear yard setback requirements for the district. Section 8 reads:
In the "R" District, an accessory building shall not occupy more than 25% of the required rear yard. An accessory building attached to or detached from the principal building shall be subject to front, side, and rear yard requirements applicable to the principal building, except that in the R-15, R-20 and R-40 districts the minimum side and rear yards for an accessory building which is detached from the principal building shall be 15 feet. Detached accessory buildings in the "C" and "I" Districts shall be located on the lot so as not to violate the minimum open space requirements set forth in Schedule A. An accessory private swimming pool in any district shall be completely enclosed by a fence at least five feet in height having a self-closing gate with a latch. No permanent swimming pool or any appurtenant structure thereto shall be located within any required front yard nor within 15 feet from any side or rear lot line.
Please call the office with any specific questions you may have relative to your property.