I do think steel frames are more efficient and generally a better way to go, but how do you address the thermal bridging. Apparently the 6 star energy ratings don't recognise the difference between steel and timber at the moment, but do for commercial buildings and the rating guys are finding the difference significant. Id really appreciate any information you have in regard to this.
Your best off going with exterior insulation instead of insulating in the cavities. Less thermal bridging & condensation issues regardless of wood vs steel framing.
