Hi Renai, there are a couple of things about the kitchen that trouble me. To me in some ways it looks like a hybrid of 1990's kitchens and the current direction design is taking. The L-shaped return looks like it has a breakfast bar, but so does the island bench - a duality that does the kitchen no favours. I would ditch the L- return. This achieves a number of things: 1 - It facilitates better traffic flow between the kitchen and dining room; 2- it eliminates the awkward corner cupboard, always a problem that none of the many high tech "solutions" address adequately; 3 - it simplifies the construction of the kitchen, with potential savings; I would move the island bench up the page (possibly even make it longer), providing a free wall for tall storage cabinets, and or alternative fridge location. The door to the walk in pantry would need to move slightly to best achieve this. The corner location where you have the fridge now is not good for one main reason: you will often need to open fridge doors up wider than 90° to pull out drawers and shelves for cleaning, and even at 90° most modern fridge doors require more space than just the fridge recess allows.

I'm no expert but just my thoughts if it was my house - The bedrooms are on the small side, so perhaps think about how they will be used - do your children need space to play or do homework in their rooms? Is the 4th bedroom for guests or will it be used as a home office? In bedrooms 2 and 3 the beds are below the window - are the windows high enough to allow a bedhead/to not lay down with your head against the window? What will be in the main bathroom - shower, bath, single/double vanity? What are you thinking layout wise? I'm confused by the kitchen, especially the pantry access given the corners are blocked by other benches - is it meant to be a walk in pantry or just normal cupboards? The hall is long and narrow and you need to go past all the bedrooms before you get to the living space. Not sure how well this will work, but I've only lived in places where the entry is adjacent to living space. Love the idea of having a separate self contained space for your parents - as others have said bathroom is too far from either bedroom, and the entry near bedroom could be an issue.

before making any realistic suggestions we need to understand the existing spaces but your plan shows bed 2 and 3 as projecting out further than bed 1 but the roof doesn't show a corresponding change of shape?...assuming that the roof is correct you need to add dimensions for width of kitchen, laundry, toilet, bathroom and width of original bed 3 and can you please show locations of windows and external doors and what is space beyond the existing living? ... pending confirmation of details my suggestions would be to build new kids bedrooms and bathroom at the back with part of bed 3 as the rumpus, have a master suite at the front with part of bed 3 as wiw and original bathroom as ens and powder room and rearrange the old laundry or add a new extra laundry with the new kids rooms and use original laundry for a pantry...the biggest challenge will be the new roof but maybe the extension could have a skillion roof tucked under the original eaves but that depends on available ceiling heights

my suggestions includes others' ideas and reduces the size of the whole building by about 20 sqm, uses the verandah space to create a mudroom laundry connecting garage to kitchen, has an internal family bathroom with ventilating skylights and a laundry chute, simplifies the roof but still has two living areas, 4 bedroom, study, WIP, WIL generous kitchen and lots of extra storage with a separate entry and front porch and, as the house is shorter and narrower there's more set back from boundaries to allow for water tanks and AC and perhaps a garden along the northern side