I expect to get the approval for my planning application (well, building
warrant) from the council any day now, and would like to go ahead with the
work ASAP.

This involves knocking down a wall to allow me to connect two recesses and
create one new room (to become my kitchen), and open a doorway in another
wall to allow for access into this room.

I am in the top floor of a Victorian tenement building, and the wall to be
knocked down IS NOT a supporting wall (all the plans were drawn by my
architect and structural engineer), and the wall in which the doorway is to
be made is, again, not a supporting wall.

My mate, who is a joiner with 15+ years experience, and who will help me
with all the major joinery work has suggested that we will tackle the
demolition work + installing the new doorway ourselves.

My mate is very sensible and would not have suggested this had he not
thought that we were able to do this. It is just that I don't want any major
problems/expenses resulting from this.

Is that a good idea in general? Anything to be concerned about? I forgot
to mention that my structural engineer has specified exactly how he expects
the building work to be carried out (which order, and which supports to have
in place prior to starting, etc), and we intend to follow them.

Thanks in advance.

PS: all the walls + ceilings in and around the areas affected by the work
are going to be plastered as soon as the work is complete.