We put a deposit down on a new home purchase and have decided not to purchase the home, can we get our deposit back?

The purpose of the deposit is to obligate you to the builder to purchase the home.  However, read your contract thoroughly to determine if there is a date by which the contractor has not performed all of his obligations under which he was required to perform.  There may also be an assumption clause in the contract which may allow you to sell your purchase contract to another buyer.  You may wish to contact a local real estate attorney for further details.