Also, some of the designs that I've seen, with the house effectively built on steel & concrete stilts/plinth should also potentially reduce termite invasions. (Is yours on stilts ?).
Thats only half of the solution as termites here have an airborne division.. Bok BOK!! These little bast@rds are wood borers.. Ive seen holes in hardwood here 1/8th of an inch in diameter.
They lay their eggs in the hole and the new born bore tunnels.. Hundreds and hundreds of tunnels.

I started my search looking at US and Aussie companies as I expected their kits to be of a reasonably high standard (due to Health & Safety etc etc)...... but if some of these have exported to Philly and got local building contractors to do the construction, then why not just buy the design & get the local contractor to source the building materials & do the construction ?
Exactly.