advise on structural details Single Room with bathroom in loft with rear Domer

[Mubbashshir]

The plan is to have loft room with rear domer&attached bathroom. However need advise on loft room location with possible locations attached in snapshot "Rear_view_with_two_Possible_Locations_of_LoftRoom"

attached pictures gives good idea of possible loft room locations i.e. location 1 or location 2 from inside and outside along with comments in the snapshots

 

Need advise on the below : 

1. Rough drawing of loft room with rear domer with bathroom with structural changes such as steel beam in loft floor or in domer to ensure stability will be very helpful. 

2. Advise of how to manage the party wall if we have to slot steel beam in the wall along the neighbours side. 

3. Ensure all the details are discussed with builder with regards to the plan and material type etc which will be used so we don't incur additional cost due to constant changes.

4. Advise of the stairs location 

 

 

Edited March 6 by Mubbashshir