Q: Our local energy utility recommends framing exterior walls with a single top plate to cut down thermal conduction. We follow the CABO code when we do this, making sure we line up trusses and/or joists directly over the studs. We splice the top plate joints with Simpson TP37 straps for 2x4 walls and TP47s for 2x6 walls, using three Teco nails on each side of the splice (the code actually calls for three 8d nails on each side). Even though the single top plate is approved, I still get comments from subs and carpenters that it doesn’t look strong enough. I wonder, from an engineering standpoint, whether this method is as strong as using the traditional double top plate?