We signed a contract with a construction contractor for windows, siding, soffit and facia. During the job, we noted that the patio door which was installed opened the wrong wayand he admitted blame and stated it would be changed. Towards the end of the job, we noticed that the windows were ordered standard (not low e and argon as verbally agreed). We would like to hold the contractor to his contract which states "Low E" but not argon (because of the energy savings). We had a meeting with him and he stated that he would change the windows as contractually obligated, then he handed us a receipt which then had a bunch of new additional charges for $3200 more than the original contract stated and said he would not change the patio door. The bulk of the new charges $2,300, are for insulation installation and Tyvek. Insulation and Tyvek were verbally spelled out as part of the job (also, as required by building code so they would be required materials) and at no time during before or during the job was it stated we would get charged. Most of the other charges are unworthy as well verbally agreed upon as the job progressed with no ammendment to the contract. His contract is very simple and states "Contractor is to include all labor and approved materials, appliances and services of every kind necessary for proper execution of work. Contractor shall re-execute any work that fails to conform to the requirements of the Contract." There are no stipulations in the contract regarding owner is liable for any additional charges, or additional materials. However, there is one clause, " The contract sum is based upon the following alternates, if any, which are described in the Contract documents and are hereby the Owner, NONE". The situation is a little more complicated than just this, however, this is the major part. He threatened to put a lein on the house, tear down the siding and remove his insulation materials. It is a mess. Currently we are holding $2850 of the money until we can resolve the matter. I seek your advisement on a course of action. Do you think I may have to pay these additional charges? Can he lien on my house? Such I forget the correct windows and just cut my losses and try to negotiate correcting the just the patio door and some other very minor workmanship problems?