Under the Massachusetts Mechanics Lien Statute:
The contractor is supposed to file a notice with county or district clerk (where the property deeds are filed in your locality) which states that the work has been substantially completed. The contractor's lien is not technically good unless the contractor can confirm that the work is substantially complete. The law states that substantial completion means that
The law states the following on how the contractor can enforce the lien:
Section 5. A lien upon land for the erection, alteration, repair or removal of a building or other structure or other improvement of real property or a lien established under section seventy-six of chapter sixty-three, section six of chapter one hundred and eighty-three A, or subsection (a) of section twenty-nine of chapter one hundred and eighty-three B shall be enforced by a civil action
brought in the superior court for the county where such land lies or in the district court
in the judicial district where such land lies. The plaintiff shall bring his action in his own behalf and in behalf of all other persons in interest who shall become parties. An attested copy of the complaint, which shall contain a brief description of the property sufficient to identify it, and a statement of the amount due, shall be filed in the registry of deeds and recorded as provided in section nine within thirty days of the commencement of the action, or such lien shall be dissolved. All other parties in interest may appear and have their rights determined in such action, and at any time before entry of final judgment, upon the suggestion of any party in interest that any other person is or may be interested in the action, or of its own motion, the court may summon such person to appear in such cause on or before a day certain or be forever barred from any rights thereunder. The court may in its discretion provide for notice to absent parties in interest. The terms “party in interest” and “person in interest”, as used in this chapter, shall include mortgages and attaching creditors.
Essentially what this means is that there is a trial. I'm not sure where you are in this process. You mentioned the possibility of a sheriff seizing your house. If you are at this point in the process, that means its probably too late to be able to fight as there has been a judgment issued against you.
If there has not yet been a judgment issued against you, then you need to go to each and every court proceeding. You need to argue that the contractor did not "substantially complete" the house and that you can't use it because it is not complete. If the work is not complete, then they don't have a right to execute the lien.
The contractor had to serve you with notice by certified mail that he had a lien on the house (see the statute). If he did not follow the procedures with serving you with notice of the lien, then he does not yet have the right to execute on the lien.
If possible, you need to go to court and argue that the lien is not enforceable because you did not get proper notice of the lien as required by the statute and the work is not substantially complete. You need to file an "Answer" to the lawsuit filed against you and state that you "generally deny each and every, all and singular, allegations in Plaintiff's petition." You also need to state that you deny that the Plaintiff has complied with the requirements of the mechanic's lien statute in regard to notice. Also state that the Plaintiff has not substantially completed the work it promised to complete under the written agreement and thus is not entitled to enforcement of the lien.
If at all possible, hire an attorney to represent you. However, it sounds like money may be tight and this might not be possible, so you will have to represent yourself. When people come to court the judge will generally help you. Don't let the contractor's attorney run over you. If you stand tough and make arguments against them, then you may be able to negotiate enough time to find a loan to pay the contractor.
I hope this helps. Let me know if there's anything else I can do for you.
Zachaary D. Norris