we need dimensions of all the rooms, what are the walls, floors and roof built out of ..and a view of the roof from Google earth will help

Honestly? If the main idea is to just move the living area into a north aspect this is easy without an extension. Turn the three bedrooms into an open plan kitchen/living area and put the bedrooms into the existing kitchen/study/living area's. Your current floor plan is almost symmetrical and since your house in on piers and not a slab moving the plumbing will not be that expensive.

Building out is the most expensive renovation you can do, but I think you can achieve your aims without it.

The missing internal dimesions are the bathroom (2.1 x 2.7), current powder room (1.85 x 1), hallway width 1m in smaller section, 1.5 in entry area. External walls are brick veneer, no internal brick walls. House is on stumps, wooden floor - except laundry which is a lean to on a slab. Tiled roof except for the laundry.

Here is a Google Maps satellite view.. The deck roof at the back is tin/laserlight. We would need to play around with the deck roof to get northern light into our extension plans. The planned extension would go to the end of where the current deck roof is...

what's the distance from the house (ignoring the existing deck) to the back fence

Austere - we actually need to retain the four bedrooms, and we were wanting to have a seperate lounge in addition to an open living/dining/kitchen, which is the main idea around a small extension. But I have considered re-orienting the living space to the northern side of the house, it just sounds sounds more dramatic and difficult, moving things around like that... If we did move our living to that side, what sort of layout would you suggest? I find it hard to imagine the best place for the kitchen with that idea.

oklouise - roughly 4 metres to the fence on the east side

How ere you proposing to retain the 4th bedroom when you plan to turn it into a separate living area adjoining the kitchen? Your revised plan with the changes only shows the backend of the house, not the full floorplan. From that I assumed that the current 4th bedroom was being repurposed as a dining/living room and you were retaining the original 3 bedrooms.

If you look at the original house fllorplan, it's a H shape with what appears to be two equal sized wings. One of them houses 3 bedrooms while the other the current kitchen, 4th bed/study and the dining room. Flipping the house into a mirror image will require moving the walls of the current dining/kitchen and study to create three bedrooms the same size as your existing ones.

The kitchen would then be positioned in the [current] centre bedroom space with an open plan dining, living towards the rear. There is no need to install a U shaped kitchen as you currently have. A galley style that runs across the space will be more space efficient and give you a large island to work with. While the front part could be your 4th bedroom or you can relocate your current front living room to that space and put the forth bedroom where the current living area is. It's really not much different to the floorplan you have in mind, it's just a mirror image of it placing all the bedrooms in the south and living area's in the north as is desirable.

Unless you are planning to move out during the build it's going to be difficult living in the middle of any renovation. Your builder will have to remove the rear wall of your house to extend and you'll be living in a house with tarps on the backend anyway. Any renovation can be staged to cause least inconvenience. But no matter what, changing the footprint of a house is always going to be a major hassle. Which is why a lot of people choose to move out and rent for the duration of the build.

I agree. Flip the house plan. You could add an en-suite in the alcove outside the bathroom. It does mean adjusting a lot of internal walls though. But if you plan to live there for 10 years I think the quality of living will be better. But maybe that depends on standard of current finishes

Get a builder to assess

Sorry I left off the other part of the plan was to seperate the current dining and living into 2 seperate rooms, one to be our fourth bedroom/office space, and the other to be the seperate lounge.

Austere - you have a very interesting idea... Would that be enough room for an open kitchen/dining/living space - it would work out to be 4 x 7m? I do really like galley style kitchens, from a functionality perspective, so I do like that idea too.

Having lived through half of our bathroom renovation living at the house, and with two young children we would definetly be moving out for any extensive reno.

i think the existing roof and laundry will be more complicated to repurpose than you hope and the dimensions are inconsistent and, while kids are small, the extra toilet may not be missed but my suggestions includes using all the available space to make a modest ensuite with it's own toilet and the basic laundry but you'll need careful attention to achieve the best roof shape so i'd be talking to a builder about potential issues with removing walls and alternate extension options before finalising any design ... subject to available space to the north you may find that it's more cost effective to use the bed 4 as a dining room (like my last years suggestion) without extending for now and long term plan for an extension behind the garage or to the north but your basic idea could work with a simple skillion roof

Wow, thank you so much for taking the time to do that oklouise, it's a great plan. Better than my original! I think you might be right, that the laundry would probably end up having to go...

The inconsistencies I can see are the hallway - it's only 1 metre wide around most of the house except for the entryway.

I have been thinking a lot about the suggestions offered on this thread to move the living space to the north side of the house, and wonder if, with a small extension where the current laundry is to meet the bedroom 4/study wall it would work? I have played around with it and come up with this design. It doesn't offer a WIW or ensuite, but there is a good sized space for a second bathroom.

We have actually spoken to a builder about this type of extension before, as the footprint was like this on our earlier plan. He thought it would be best extending the current roof line, and so would be possible, not the cheapest, but doable.

Thanks for all the helpful comments so far. Your thoughts on this would be great too.

happy to help but can you please walk through the house and measure every room so we begin with a plan that is closer to reality.. measure the length and width of each space and add to this blank plan ...we also need to understand the short and long term plans for the house..do you urgently need an extra bathroom and bedroom, new kitchen, more comfortable living area etc? do you prefer to have a bigger mortgage and do everything at once or make a whole house renovation plan that can be reduced to segments that can be added over time.. changing the bedrooms into a new north facing living area is possibly a great idea but does this latest plan provide everything you want and for how much.....what is the distance from the north side of the house to the boundary what can you see past that north fence and have you considered using the space behind the garage??

I have measured everything, let me know if there is anything you can't read

When we brought our house we were thinking it was a 10 year plan, although the more we live here and make our mark on the space, I think it could be our forever home. Short term we need an open living space where I can see the kids while cooking or pottering around. I also really want to connect the house to our deck which is underutilised due to the current layout. Longer term, we will need extra space, which is why a separate lounge appeals.

I like the idea of doing things slowly, although my husband wants to do it all at once. So if we did do something major we would do some big parts first and then stagger the work that isn't as urgent - like the second bathroom for example. We need four bedrooms, although we can live without one for a little while if we need to put off fixing one up...

I think a northern exposure in the living space with a connection to the back deck ticks a lot of boxes for me, which means I could live without a WIW.

We are on a corner block, and there are trees and houses that we can see through the northern windows. We are currently doing some landscaping on that side of the house, and plan to plant a hedge along the fence which could grow tall, and a nice garden, so the view would eventually be pretty nice. It is 4 metres to the fence.

I hadn't considered doing something behind the garage, although we do use the lawn there quite a bit, so would be hesitant to do that.

the space around the old laundry would be good for a new kitchen but my suggestion has a bigger extension that includes the new kitchen with a dining area and northern aspect and access to the garden on both sides, connection to the new family room made out of the 2 northern bedrooms with, either a portion used for an ens (or an extension that could help improve privacy for the northern garden with a more generous master ens and wiw) the old kitchen and dining area is converted into bedrooms and the rear hallways and toilet rearranged into a walk through laundry and powder room..seems ok in theory but the new roofs would be extra challenging although a simple skillion roof could work if there's enough height under the eaves..but that would need a careful on site inspection by your builder and architect

That's great oklouse, thank you so much for taking the time to do that up. It's a lot to think about... I really appreciate all of the advice.