reluctant to lose the convenience of outside access to a toilet my suggestion sacrifices a little space off the lounge and bedroom to keep the extra toilet and use the original laundry space for a bigger ensuite with separate toilet and double vanities, the new extension makes a more spacious wiw with only standard doorway openings to the new rooms but the ideal outside door for the laundry will depend on the location of the drying area and you may decide that a western door or no outside door (and walk through the verandah?) could both add more counter space to the laundry and, much as i like the gable roof for the extension, it would be interesting to obtain a comparative quote for a simple skillion roof (and raked ceilings for the new laundry and wiw) that may save a lot of extra roof structure that doesn't add anything to the inside of the new rooms or streetscape and could be much cheaper..

This is my bedroom/ensuite set up. Overall our rectangle is 3960 x 8030. this concept with WIR first then ensuite may work. However your bedroom size may have to be reduced. The measurements of spaces are along the top of plan. Orientation would be the same as my plan, just entrance door/window position would change.

Thanks so much for your input. Re the downstairs floorplans: we prefer to keep the study away from the family area to keep it quiet, so will probably leave it as is. However, I have been thinking more about the downstairs bathroom and your comments to move the laundry. I really think the downstairs bathroom was too small for a family bathroom so I have expanded it by stealing the laundry space, and taking space out of the pantry ( which was very generous) to make space for the laundry. This also allows a separate toilet. I don’t need outside access for the laundry as we would hang the clothes on the other (west) side of the house. Would just need good ventilation. Once again I am very grateful for your input! Old followed by new posted for comparison.

This would be cheaper