The foundation is what provides a good portion of the stability for a structure. When there are issues with the foundation, the entire structure might be unstable and unusable. This isn't ever something that you want to deal with in a new construction.
It is imperative that anyone who owns a building or has contracted with someone to build a new structure understands some of the common warning signs of a foundation issue. There are a few ways that you can spot an issue in these cases.
First, look around the inside of the home. There shouldn't be a lot of shifting. An unstable foundation will cause the home to shift, which can lead to doors not closing properly or windows not opening and closing. It is also possible that you will see cracks in the walls or ceilings. These are common around stress points like around windows and doors, in seams and in the ceiling.
Second, check the concrete of the foundation. If there is a bit of concrete that you can put your finger on, grab a hefty screwdriver. Poke at the concrete. If the foundation is sturdy, you won't be able to damage the concrete. If the concrete is damaged by the screwdriver, it is weakened and is likely the cause of the building's issue.
Third, look at the foundation to see if there are cracks. Very small cracks and those that occur in an L-joint aren't usually a big deal. Jagged, large or horizontal cracks are more serious and signal the need to have the foundation inspected.
If there is a foundation issue that can be traced to the contractor doing something incorrectly, you might opt to pursue compensation. Correcting foundation issues can be very expensive.
Source: HouseLogic, "Identifying House Foundation Problems," accessed April 27, 2018