I asked an acquaintance to work on the house; now we have a legal mess

A while back I asked an acquaintance to perform some work on my house. He started the work but has not finished. When he was a little over halfway done with the project, we started to disagree regarding how the work was to be performed and the terms of our agreement. I dug around and found a copy of an agreement that he gave me with his signature before he started work. However, my signature was not part of the copy. Is the copy a valid contract? If I want to just get out of the contract, can I since my signature is not on the contract? Do I have to pay him the full amount?

This is a very difficult question to answer without more facts. The answer to this question depends on a variety of factors including the nature of the work performed and the promises that were made.
Every valid contract contains basic elements including an offer, acceptance, and consideration. Consideration refers to the mutual exchange of benefits or detriments.

At a minimum, the fact that your acquaintance rendered a significant amount of services may be sufficient alone to have created a contract along with your verbal agreement of acceptance. The services already rendered could create consideration.

Generally a copy, or what is referred to legally as a “duplicate,” is sufficient evidence of the existence of a contract where the original has been lost or inadvertently destroyed. I will assume from your fact pattern that this is probably the case in your situation.

Regarding your latter question but in relation to the enforceability of the contract against your acquaintance, the general rule is that one can enforce a contract against the other party as long as the other party has signed the contract. All things being equal, if your acquaintance signed the contract, you can probably enforce the contract against him.

Consequently, if the copy of the contract has terms favorable to you, you can probably use the copy of the contract to your benefit.

On the other hand, if you want to just terminate the contract, the fact that you did not sign the contract alone may not be enough to relieve you of your contractual obligation to allow the other party to complete the work and pay him the full amount. With many service contracts, an oral agreement can be sufficient to create a binding contract. Further, as discussed above, your acceptance of a significant amount of benefits already could constitute consideration.

Although if your acquaintance had a contract with your signature on it he would be in a stronger position for enforcement, he may still be able to establish the existence of a contract between the two of you. The fact that he has completed potentially a substantial portion of the work already acts in his favor in contending that a contract exists.

Of course there are many other factors that would determine the outcome of this question. If the other party has performed poor quality work or otherwise breached the contract, you may have an outlet for terminating the contract.

There may be an implied warranty of workmanship or basically legal requirements that the “contractor” complete the work in a satisfactory manner.

Nonetheless, you may still have to pay for the fair value of the services rendered at this point.

All legal theory aside, hopefully you and your acquaintance are able to come together and arrive at a resolution to your disagreement.