While we cannot comment on the work or word of a professional, one benefit of having a company treat your home is they do provide a warranty. What that warranty is would need to be asked of the company and any contract they may have had with you. While
Termidor SC can last in the soil for 10 years or more, it does not guarantee you won't have termites for 10 years. The 10 year applies to the areas that you apply Termidor, it is guaranteed to stay where you put it and protect and last for 10 years. However, no termite treatment can 100% guarantee that you won't have termites because termites can enter your home in places that you cannot treat, like underneath a slab, through a plumbing pipe, or through an area you cannot get the treatment to because it is covered or inaccessible. If any of the soil was disturbed, a retreatment may need to be done. After your home is built, it is impossible to get to every entry point. There are always areas you cannot get to which is why you should continue to have a professional company come out every couple of years to do a professional inspection to make sure you have no areas of activity.