door opening

[Mikest]

I have a existing rear living room extension, and will now be building a kitchen that will level off it.
Im putting in a door from the kitchen to garden.

Any one know if its o.k to attach one side of a door frame to the existing extension and the other side to the new extension wall.
I read there has to be a insulated cavity closer on each side of opening, would i have to attach one to the existing extension wall.

Could there be any problems with regs? heat loss etc.

 

[RedHerring2]

I'm doing exactly that. The door from the dining room to the conservatory will be hung, one side on the existing solid double skin wall and the other side on the new cavity wall. Obviously, I'll only be able to use a cavity closer on one side. Whereas there's no reason for you not to insert a cavity closer in the existing wall.
I assume you are using an insulated lintel across the top?

Incidentally, use a cavity closer across the bottom also.

Another point, use wall ties at every course in the new wall at the unbonded jamb.

 

[^woody^]

The only criteria is for a vertical DPC up the jambs, and maybe a thermal break - but there is no specific requirement for an insulated cavity closer