Door frames & isolation

Now preparing the doors on our studio build and am looking at some options for the frames. I am using a room-in-room design with a single heavy duty door. I am reluctant to join the walls together with the frame surround even though this would give me greater strength and stability. I have in fact heard that joining the walls at this point does not however decrease isolation significantly but am still reluctant ? If I do mount the frame to the inner shell only, I am uncertain how to close up the gap between the walls correctly? Should I perhaps use a double skin like the main walls but try to limit the contact on each side - or perhaps there is an easier way ? Thanks for sharing ideas and experiences in this regard !

If you are using only a single door on two leaves, then you have no choice: you HAVE to join the leaves together with the door framing. If not, one of the leaves is entirely pointless, as it is incomplete... Also, your air gap is open to the world... And yes, joining the two leaves does create a flanking path between them, and does compromise isolation, to a certain extent. So I guess that begs the question: Why do you only want to use one door on a two-leaf wall? Is there a major overriding reason why you can't put a door on each leaf, in the normal manner? - Stuart -

I have seen many designs using a single "super door" including those in Rod Gervais book and thought I would consider that option. Rod states in his book that the flanking effected created by joining the leaves in negligible and I was hoping to hear from forum users about their practical experiences of doing this. The reasoning for utilising a singe door is financial savings on the ironmongery etc as my studios will have 6 doorways and those costs add up. Also physical space restrictions are a consideration. I would also prefer the doors to open into the rooms only and not also out into the passage. I am looking at constructing a very heavy "superdoor" that should perform well (though I realise not as well as two separate doors !) I am trying to find an article I once read that describes how to seal the space between the leaves once you have mounted the door on the inner leaf so as to avoid as you say "your air gap is open to the world..." Thanks for taking the time to respond and while I understand and agree to the points you are making I still wanted to consider my options in this regard . .