Big open space or keep as separate rooms - your experience?

[Nevermakeit]

We are looking to do an extension on the back of our kitchen, to make a big, family room (dinner table and sofa area).
We already have a medium sized sitting room in the front of the house (2xsofas, TV, piano basically).
The idea would be to put a utility room in the centre of the house (between the 2 rooms mentioned above), as there is no natural light there - and it would be both utility and general dumping place for pantry items, roller skates, tennis rackets and the like.
One architect I have spoken to has recommended this solution, but another has said it's a shame to lose the opportunity to knock down that wall between the sitting room and new extension (clearly will then never be possible as the utility room will be between both) - especially as the house is north facing.
I have 3 DC (currently aged 10,8 and 6), and whilst I love big open spaces, I think in future it might be better to have separate rooms so one can watch TV whilst another plays the piano etc - though I suppose we could put a glass door across.
Does anyone have any thoughts on this? Has anyone regretted having too big an open space (this would basically be whole ground floor except hallway and downstairs loo), or on the contrary regretted not doing it?
Any inputs welcome!

I was going to say what you said about TV etc. Houses need a separate room for noise, they just do. Kids grow and need storage for homework, music practice, TV etc and postscript need to be able to escape it all!

We have a nice extension with kitchen, big dining area with space for comfy armchair but have kept a separate living room and it works well, we have a big space to congregate but can also close doors on each other!

*parents.

There's a thread on Property/DIY about this at the moment:

Do you think lockdown will make open plan less fashionable?

We have a big open kitchen/family room, small utility and separate sitting room. I am so glad we have the separate sitting room. The DC watch tv there so they can be near us but we don’t have to listen to Teen Titans or whatever. In lockdown it was fab as a place for older DD to do her online lessons whilst younger dd was with me. It’s a place to go and read quietly or do a quick bit of work away from the kitchen noise.

We do have doors between the sitting room and the big family room (our utility is on the other side), but we hardly ever have them open.

I would definitely recommend the separate sitting room. Unless you are all willing to use your bedrooms to escape to, even in the middle of the day.

I'd definitely keep a separate sitting room.

It's nice for people in the family to have some space to escape to - especially teens if they have friends over, or even as an adult to read a book or similar whilst others are watching a movie.

Also in winter it's nice to have a cosy room with a fire.

I can't see any benefit in opening up the whole space - actually the reverse.

You get a great open plan kitchen/dining family room already - if you CS have that plus a utility/pantry and a cosy lounge why would you want one massive open echo chamber?

Keep the separate spaces. It's nice to have that delineation. You live in a home, not a village hall.

Yes, keep the space separate. It's an escape room when you need p and q or for your children as they get older.

We expanded the kitchen/dining room into one big room, and while it made sense at the time, we are now in the process of putting the wall back up to turn the dining room into a snug/tv room.

Lots of reasons, but mostly as the open area wasn't really one thing or the other. Not a proper dining room, nor a proper kitchen.