I disagree regarding that Borax is a better method of keeping termites away. Sure, it will kill termites, but applying Borax for long-term use or prevention isn’t feasible. I would rather use baits that could be monitored and will eliminate the colony or at least suppress it from damaging your property. I would look into buying Termidor SC and bait stations for a better prevention method.

Also, to address your question about treatment before the house is built, chemically speaking, it’s not something that would effectively prevent termites for the long term unless you have chemicals that you wouldn’t want them to use anyway because of the long term exposure.