With recent changes in energy codes, continuous insulation and continuous air barriers are now required in almost all climate zones.  

Several years ago while working on a Colorado shopping mall I was surprised to see the Design Development drawings I was reviewing indicated insulation at the low-sloped roofing assembly as a mere R-11. The climatein this part of Colorado, as with most of Colorado, is cold—really cold. 

 Air barriers have recently been identified as one of several effective and viable solutions toward better high-performance buildings.