ETC

I really think you need professional advice. You should really speak to a civil engineer who specialises in basement construction.

They won’t. With a roof conversion you will need EEW from each first floor habitable room plus an interlinked SAA no more than 3.0m from each bedroom door.

Sounds like you experienced some very poor customer care. If you are very unhappy with how you were treated drop the ARB and RIBA a line. I presume she is Registered and Chartered. I’d love to see the drawings if you want to post them or pm me. Can you elaborate a bit more about what you would like to achieve and where your stumbling blocks are.

No stepped DPC above the telescopic vents?

The plan is simple enough - the roof is another matter. Plus building on the boundary - as others have pointed out - could be problematic.

Get an architect - you'll get a more elegant solution.

If you ask nicely I might even do a 3D of what I am suggesting!!

Calm down dear! I was only suggesting a (much cheaper) alternative to what you are suggesting.

Bookcase either side. Frame out a window seat. Simple.

Here’s a thought - why don’t you form the window seat inside the room?

For the ironing.

A few pieces of information.

It should be placed behind a vertical DPC to protect it and as far as I know fixed to the timber frame.

Take out the PIR and put a timber batten to close the cavity.

Plus you need to sort out how water is getting inside.

You need 1/2HRFR. Will these give it?

DPCs not placed correctly at the jambs. Open up a jamb and see how the DPCs have been placed.

It would be better to place the doors (and windows for that matter) in line with the back of the outer leaf with a vertical DPC. You will also need cavity barriers to the perimeter of the opening. TF normally uses a timber batten but you can use bagged cavity barriers.

Absolutely - a complete waste of money!

When’s the last time anyone saw a completely sodden canal side wall - I’ll bet my hat that it’s never seen a chemical or electrical DPC. Physics guys - just physics!