Use permits and site plan approval permits are determined based on the Zoning By-law (ZBL). Sometimes the ZBL is not clear in which case you can confer with the Zoning Enforcement Officer (ZEO who is also the Building Commissioner). The ZEO who can review your idea / project to determine which land permits may or may not be required.
It’s always best to do some research before you contact the ZEO. Start with reviewing the Zoning By-Law and Zoning Map which are your best research resources in understanding what may or may not be allowed on a particular lot. The Town’s website has a number of on-line tools to help you gather the information you need such as the Assessor’s database (property record cards), Zoning Map & GIS, Zoning By-Law (on line, searchable version).
Please contact the Building Department to reach the Zoning Enforcement Officer.