A plan would be great - much easier to visualise...for me anyway.

Here is the floor plan for the house.

height of the windows ? above floor level?

Louisa I have to ask if there is a reason for separating the bedrooms & the placement of the dog room? To me north is where you want to open the house to unless there is a good reason like views, privacy issues or otherwise...

Are you averse to changing the layout to improve the flow & function of this house? For example bedrooms together, plumbing together, maximum use of north facing walls for winter sun, west walls for service rooms to shield internal spaces from heat gain from hot sun etc???

Western wall will have a carport attached so will be shielded from sun. Western 'wall' of carport will be mesh with a creeper grown up it. We live in Gladstone SA where we have a long hot summer and a long cold winter. We have built houses before that make use of north facing but have found since we have lived here that having lots of south facing windows is also very important for light without sun coming in and for when a cool breeze is present. Shower room is on the north side so that it dries out well and doesn't grow mold. North wall will have a pergola with a deciduous climber on it. The second bedroom is a spare room - children have gone. The dog room does not have solid walls. It will actually be cellar balustrading - the dogs are in the room without being all over the furniture. Their spot is there because it gives them access to the yard (there will be a dog door in the wall).

The house is actually a converted shed. We are using secondhand products as much as possible. Windows in the living area are 1800H but have to be 500 off the floor or we have to reglaze them with safety glass (they are old windows). External doors are both glass.

Our taste is country/shabby chic/reclaimed/antique. We already have plenty of furniture, just not sure how to arrange it and wanted some advice

There will be a lack of Loungeroom storage, so use a chest or opening ottoman as a coffee table.

Have you considered moving the laundry & store to the kitchen end with direct access from the carport? Storage could double as pantry space.

I see the vanity area could be improved as the door configurations restrict flow in this area to laundry & shower. Especially for any future mobility issues.

Instead of having an ordinary door on the north side of the second bedroom, and a solid wall on the east side, why not have French or big pocket doors on the east side, so that, when you don't have guests, the second bedroom can function as part of your living area, and when you do, it can be closed off?

That bedroom will get used nearly every weekend when one child or the other comes home. Nice thought, though

It's a good size. Here's a suggestion that gives separate lounge and dining zones with plenty of wall space for cupboards or book cases. As the chilren are not there all the time, a tv against the wall of bedroom 2 is an option. Good luck with it.