It is always better to prevent the appearance of the enemy on your territory than start a war with him. This is especially true when it concerns termites. The right thing to do is to do termites prevention at the stage of building a house. You have to use special impregnation for walls that will protect wood from termite infestation, such as Rust-Oleum Wood Preservative. Other preventive measures can be found in our article The Complete Guide to Getting Rid of Termites.