Licensing  

The state of Mass has many licenses available for trades people. The obvious ones are Plumbing and Electrical. Believe it or not, most plumbing and electrical can be done by the homeowner. Personally I would rather leave it all to the professionals. Poor Plumbing leads to extensive water damage and I should not have to tell anyone what happens when you play with electricity. If you happen to be handy and try some of this by yourself have a professional come in when your done and look it over for safety sake. A couple of things that you absolutely cannot perform without a license are:

Electrical

Anything from your electrical panel to the street is strictly off limits. You can run wires up to the panel, but a licensed electrician must install them to the panel. As I said previously, unless your changing an outlet or maybe a light fixture, leave the rest to the pro's.

Plumbing

Most inspectors do not condone homeowners doing plumbing but as a "occupying homeowner" you can do you own plumbing. Things you cannot do are hooking up to a boiler or heating system and external work such as leaching fields, tying into town systems ect.

ALTHOUGH YOU MAY DO SOME OF THIS WORK. A PERMIT IS STILL REQUIRED.

BUILDING

Mass has two licenses available, a construction supervisors license, restricted and unrestricted. Restricted limits the license holder to one and two family dwellings, and the unrestricted is self explanatory.

 For virtually any project you have in mind a building permit is necessary. Any alteration, change, or demolition falls under permit requirements.  Never feel embarrassed to see a Contractors license. You can even ask for a copy. Some say they are licensed? ask to see it. The License is required to be on your person at all times during a project, if they don't have it with them they probably do not have one at all. In order to get a permit the town will need to see this license and their HIC card ( see below ).

The "Home Improvement Contractor" or H.I.C. card is a guarantee fund set up by the state to help customers who have been taken by bad contractors. ALL contractors are required to have this card. Even fence Co., pool guy's, and painters. You cannot receive a permit without a current card. Even work that does not require a building license still requires an HIC card

You may check with " the Board of regulation and standards" at One Ashburton Place, in Boston for any complaints against your potential contractor.