Option 1. I wouldn't give up a 4 bedroom house with euro laundry to have a 3 bedroom house with a big laundry. I am doing something similar. We are giving up our laundry room for a staircase up to another level. We will loose the laundry entirely so it will be incorporated into the main bathroom in well designed cabinetry, actually making our bathroom much bigger, as the area under the new stairs will become part of the bathroom floor space. I don't use my laundry enough to justify having it take up valuable floor room. As long as you have a place for your mops brooms vacuum and linen and towels as well though. You pretty much need a linen closet, sink and dryer and washing machine plus space for a few baskets. I never ever fold or iron in the laundry. On Pinterest you see these amazing big laundry rooms but they are probably in houses with masses of space. Work with what u have. What's the latest on your project - what did you decide in the end....?

Hey L thanks for the comment I want to do something on the wall next to stairs where the switch is Those mirrors are for this wall Actually when I enter my house I see only 2 things one is this wall and the other straight at the back where the dining is This entry wall is 1 m wide...thinking to put these on that wall but they would look very white? Attaching my dining room photo

Could leave off the doors and use the borrowed light and ventilation from the hallway/entry. Just need to make sure you can get the 10%/5% as required. Those windows may need to be bigger. Or Have the doors with glazing (obscure perhaps) and openable like 'Aneeta' sashless and the like. Maybe have timber louvres instead of glazed teamed with the glazed doors. Or Install a skylight or two that opens (many do). Can get them with blinds to cut down on the light coming in. However go back to designer before doing anything else and have them justify to certifier why they believe it complies......

my suggestion has much less demolition including keeping the original outside back wall in favour of a simple skillion roofed extension for kitchen and alfresco, this adds a similar floor area but the shape of the extra space is much more comfortable for dining and family rooms with kitchen servery and extra storage across the full length of the dining area..the new location of stairs keeps everyday traffic out of the living area to create a more private master zone with wiw and ens, group activities in family, dining, kitchen and alfresco plus easy access to laundry, guest bath and bedroom from everywhere and upstairs for generous kids zones..new location for internal access from the garage and more storage in the entry