Every TREC promulgated contract has a place that allows a buyer or seller to have an attorney review. But most builders use contracts that their own attorneys have drawn up to primarily protect the builder. If you are not using a real estate agent, I would advise hiring an attorney to review the contract, at the very least. You need to know the answer to questions like: What if I am not happy with the construction of my home? Can I get an outside inspector to inspect home and will your builder review and address any issues from it? What if I can't get a loan after my initial pre-approval? Will I lose my earnest money and any deposits I paid? I have heard some nightmare stories from people who bought or tried to buy new construction without having a real estate agent involved. Builders are not held to the same Code of Ethics and oversight that real estate agents are.
In real life, I have had one buyer have an attorney involved--at my recommendation since the home had a "cloud" on the title. For re-sale homes, we use state-promulgated forms and agents are instructed not to insert any legal phrases. Real estate agents are thoroughly educated about the contents of a contract and the addenda so that they can explain it to their clients. We are not attorneys and cannot give legal advice however. I will say that one of my bigger concerns is how often we have contracts signed electronically without having the face-to-face conversation with our clients to make sure they understand the contract. Sometimes our clients are out of town or due to time restrictions, it is necessary to send contracts to sign remotely. Even in that case, I send a detailed summary of the contract and offer to review in detail by phone. I also provide a "Net Sheet" to my sellers to show their approximate net after closing costs, payoffs, pro-rated taxes and HOA dues. And ask my buyers to make sure they understand the Good Faith Estimate they should have received from their lender.
So unless there is an unusual circumstance, for the most part most buyers and sellers to not pay to have outside legal advice before signing a contract. Hope this helps to answer your question.