New Jersey also has an energy code go to

http://www.state.nj.us/dca/codes/

and look up under the energy code if interested. We have to do res checks now to make sure houses are "air-tight" and the recess cans have to be air tight as well. The building inspector is the one who is really the one who enforces the rules but as an electrical inspector I can tell the electrician to change the cans.