How do you fasten the baseboard in a NUDURA house?

The best way is to rip a plywood strip 2 to 2 1/2" wide and screw it in place to the webs along all the walls. Fasten these strips at every fourth web. Now the drywall contractors can set their drywall on top of it, and will cut their top sheets accordingly to suit this height. The result is you have full wood fastening for nails along the complete wall surface and the plywood is guaranteed to be covered by the baseboard.