It is difficult to know without knowing some kind of budget. The idea of bi-folds would definately modernise the space...do you mean all along the back of the terrace? Bi-folds on the kitchen window would be great and perhaps raise with a deck to be at stair level, a large bench from that kitchen window with stools for extra seating and ease of catering from the kitchen. If the budget allows it re-do the whole area so its like part of the house and not a porch add on. Search bi-fold in the search area and there are a few showing large terraces with bi-folds.

the opening into the kitchen could be narrower and the breakfast bar deeper (for knee spaces) and wider say 1800 x 900 and swop the oven and pantry so that cookware taken out of the oven can be rested on the cooktop and the coffee station could be in the corner between cooktop and sink (keeping all the hot appliances at the end of the kitchen) and forget tall pantry doors and consider having pantry divided into top and bottom sections with drawers in the bottom and wall cabinets with bifold doors only to counter height not full height and think about what to store in the cupboards...below counter 45cm wide door cnr cabinets are ideal for big appliances and less often used serving ware and giant saucepans and there would be more counter space in the corners for coffee making with wall cabinets for cups and glasses and the other corner for meal prep with wall cabinets for serving plates and the pantry between oven and fridge and try the bar fridge under the breakfast bar with a deeper overhang for stools on both sides with a stool for mum...with such a short time to delivery you need to make some fast decisions but best of luck with the kitchen and your precious new baby...this rough suggestions has only approximate dimensions and needs to be confirmed by your designer

I you are changing from stacker to bi fold doors you should ensure that there is a single door included within one of the bi folds, preferably next to the kitchen. I wonder why you are deciding between white or black windows and doors for this room when you already have white elsewhere. What colour are the internal and external walls.

" .....there has to be a better design " - that's why I'd love some input here! The 800mm gap under the box gutter will hold storage, the toilet, the 'european laundry' and the wardrobe for Bedroom 3, so certainly not wasted space. It will address all the storage needs, and will enable the garden-facing side to be quite open. No - pergola timbers are not preexisting - extending new ones from the new roof will be the primary shading device, and can have anything added to them to shade them. The box gutter enables the extension roof to be pitched upwards towards the west, creating a higher ceiling, enabling some kind of opening above the bifolds, to enable hot air to be expelled. Not that my own finances are the business of this discussion, but if I can get to lockup stage with my own cash, I can apply for a bank loan for the fitout. I'm not sure of your own experience OKL, but preliminary quotes for lockup stage were around the ballpark I'd mentioned earlier. I'll upload an updated floorplan soon :-)