The Pacific Northwest National Laboratory recommends to use a very stripped down framing method for windows & doors; namely: eliminate the jack stud and hang the header board using tie plates, and reduce drastically the number of cripple studs under the sill:
How common is that style of framing nowadays? What are the limitations, in terms of (local) code? Any recent book that would present this style in details?
The technique you are talking about was originally called "Optimal Value Framing" by the NAHB (yes, that NAHB)/HUD team that came up with it, but is more commonly called "Advanced Framing" nowadays, and is permitted in most cases by the IRC R602 prescriptives for wood framing, provided 2x6 studs are used for any assembly that is supporting more than a roof and the assembly as a whole is detailed correctly, primarily with regards to the alignment of joists and trusses with the structural members as well as the way the top plate is joined together and how the headers are set. (The only case where R602 doesn't permit the full Advanced Framing package to be used is on the first story of a three story house unless you're able to use the alternate stud spacing table.) BSI-030 provides a detailed breakdown of what's going on that's more accessible than the Code provisions.
As to how well known it is now? That's going to vary by your area, but it's something that's been discussed in high-performance-construction and building-science circles for some time now due to its inherent thermal advantages over conventional stick built walls, so high-performance builders (think Net Zero and Passivhaus) in your area should have at least heard of it, even if they use a different wall construction themselves. Production builders and finish-focused custom builders may or may not know it at all, though, and some structural engineers and even a few suburban AHJs still aren't acclimated to it, with the occasional protectionist suburban building code requiring 16" stud spacing for stupid parochial/political reasons.
