I think you should talk to a builder or architect because how many walls are moved will play a big part in the cost as adding steels is expensive. There may be a smart way of doing it such as opening up the large back area you have now but keeping the current kitchen wall (removing the doors obvs as it would be internal then).
Nice doors are also expensive and I think they have gone up a fair bit since we bought ours so you'd be looking at around 10k or so if you wanted nice sliding thin alu doors that size, which is of course the correct decision if you are not going pivot and window seat.
I'd expect near 70-90k these days tbh, without even going too nuts.
I think you should talk to a builder or architect because how many walls are moved will play a big part in the cost as adding steels is expensive. There may be a smart way of doing it such as opening up the large back area you have now but keeping the current kitchen wall (removing the doors obvs as it would be internal then).
Nice doors are also expensive and I think they have gone up a fair bit since we bought ours so you'd be looking at around 10k or so if you wanted nice sliding thin alu doors that size, which is of course the correct decision if you are not going pivot and window seat.
I'd expect near 70-90k these days tbh, without even going too nuts.