From the the Building Inspector, Andrew Lewis

BEFORE YOU HIRE A CONTRACTOR
 
Before you enter into any written agreement to construct a new home or to remodel or build an addition onto an existing home:
 
*  Ensure that the contractor is appropriately licensed and is a Licensed Construction Supervisor and/or a Registered Home Improvement Contractor.
 
*  Ensure that the contractor has adequate liability insurance and workers compensation insurance.
 
*  Ask the contractor for a written list of his/her three most recent projects with names, telephone numbers and addresses of the owners.
 
*  Call the owners and ask questions as to the performance of the contractor.
 
*  Check with your local Better Business Bureau, Board of Building Regulations & Standards and the Office of the Attorney General to find out whether the contractor has any complaints filed against him/her, or whether or not any disciplinary action has been taken against him/her.
 
For more information, click the following link to access the Department of Public Safety – BBRS website : http://www.mass.gov/?pageID=eopsagencylanding&L=3&L0=Home&L1=Public+Safety+Agencies&L2=Massachusetts+Department+of+Public+Safety&sid=Eeops