Pest Prevention in New Construction
In my area the bank would not even give you a draw for the new stage of constrution without a treatment. There require what's called a pretreat.
Which means when the foundations finished they shoot chemecals down inside the voids in the block and on the inside and outside of the footing.
Just spreading around some Boron is not going to cut it.
There's Products that can be sprayed on the bare wood that will kill any insects that try to eat the wood,
Timbor, Boracare are two that come to mind.
Any exterminator can do it for you. It's faster and not all that expencive to have them do it.