It depends on the size of the shed. All sheds must comply with the lot area requirements of Section 4.2.1 in the Belmont Zoning By-Law relating to their particular district and the side and rear yard setback requirements of Section 4.3.5 for location of accessory buildings.
If your shed is less than 200 square feet, only a certified plot plan is required with the location of the shed and other structures clearly marked. The certified plot plan insures that the property complies with certain zoning regulations after the installation of the shed.
If the shed is greater than 200 square feet, then a building permit and certified plot plan are required to show the location of the shed clearly marked. Additional information may be required depending on the construction of the shed.