You may want to contact your local licensing agency/ board to determine what warranties are automatically included with a new home. And also perhaps your state / county inspectors. You likely have some protection by law / regulation.

The structural engineer who designed the foundation for the home in expansive soils is the one to consult. If no structural engineer was involved, then no builder is going to assume that role, or the responsibilities that go with it. No warranty company will either. So, hiring a good structural engineer up front is in everyone's best interest.

I often wonder on why so much is placed on the written word and personal integrity seems to be ignored?

Thanks for the suggestions everyone. I’ll talk with the structural engineer and local resources.

Mark - in this case we are buying peace of mind since we won’t have a lot of money after this build. Our soil quality and slope adds some risk to the project. It’s an insurance policy for us. Mistakes happen - even to the best of us.

You can probably research your state's statutory builder's warranty requirements on line. Here in Virginia, home builders need to warranty the foundation of a home for five years after construction even though their warranty on other portions of the home may be shorter than that.

A lot of properties in our area have expansive (shrink/swell) soils. We have a geotechnical engineer specify the requirements for reinforced concrete footings based on the properties of the soil and the particulars of the home to be constructed.

I did the research and it turns out that New Mexico does not require builders to offer warranties. A bill was proposed in 2019 to require it but it wasn't passed and died on the house floor. The builder has offered up a policy through RWC Warranty out of Harrisburg, PA. Has anyone ever heard of them? Is there a way to research their financial standing?

Home Warranty Information for Homeowners - RWC Warranty

Consumer Info – New Mexico Home Builders Association (nmhba.com)