Seek estimates from as many builders as you can. Call your friends and ask for their recommendations. In today's booming home market, most builders are very busy. You want to find one with the time and resources to devote to your project. Put your agreement in writing.
Details are extremely important.
If the builder refuses your requests in the negotiation stage, things can only get worse later on. You should even consider hiring a real estate attorney and an architect, especially if you are building a sizable addition. You want your interests to be well protected. Your attorney can make certain the contract you sign accurately defines the scope and cost of the project. Without the architect, if your plans are vague, most builders will not spend extra money to give you such things as a solid wood door or thicker insulation.