One plan- yes others in the street have extended to the front, although most have done a full height 2 storey extension - so the precedent is there. Jen - it is a lovely layout but we have the opportunity and the money to make it perfect before we move in so would rather reconfigure it now. The combined dining/kitchen would be only 3m deep, and we couldn't extend to the back as the garden is just about the right size - we don't want to eat into it. Plus the living room feels too long and narrow at 5m deep

We have recently done something very similar. I like your idea of opening the kitchen and dining area. The island could sit fairly centrally between the two (where the wall currently is). I would also be tempted to have doors between the dining room and living room that slide into the wall, making for a fab open plan space at family gatherings/parties but can also be sectioned off during the winter for a cosier space. You don’t mention if you have a family, what your lifestyle is like so difficult to fully assess. Do you not need the office (current climate shows how we need to work from home sometimes) or do you have a relative that stays regularly hence the downstairs bedroom/en suite? If you do opt for the latter, try and configure it so that the bathroom can be accessed as a downstairs cloakroom without walking through the bedroom - perhaps jack and Jill access as I can’t see a separate cloakroom in the room plan and you will need this for such a sizeable ground floor. Keep the utility as open plan can be noisy a and ideally you need to shut off the washing machine. Think about how you live - is a separate dining table important? Do you want to be able to sit at the island or is it just extra worktop (helps denote the size). You are about to make some expensive decisions/changes so be sure this is not about trends, style over substance, balancing between what works for you and what will appeal to buyers if you plan to move on in a few years. It’s all very exciting - don’t forget to post ‘after’ pictures - good luck!

Could you put it under the stairs and knock through to use the pantry for size? or is it very low?

Which are the existing and new walls? Before considering I’d ask what really is the purpose and function of the study/bedroom as the access to it is all the way through either the utility or hallway then kitchen. Utility room could always double as a pantry and utility depending on design but even then you are having to cross a corridor to access