We have a kitchen/dinning/living space with a stove which is very functional but we have 3 other living rooms too. As children get into their teens they like their own space to hang out with friends and we use every room on the ground floor of our older house every day.
Off the kitchen area we have a garden room that gets huge use because of its view of our garden, my husbands pride and joy.
We were advised to make it open plan onto the living area years ago, but are so pleased we resisted the urge.
The privacy of that space is something we love as it opens up onto the garden and is heavenly to enjoy a drink in for a good 6+ months of the year.
If they were all to leave we would definitely downsize, for maintenance reasons alone.
I open every window every day so the house always smalls very fresh, one of my little habits.
I hate cooking smells and have tried most things.
Burning a nice candle next to cooking really helps.
Incense burnt when the kitchen is finished with for the evening, means there is never a hint of a smell of food in the morning.
I buy the inexpensive sticks that you would find in any shop selling chinese products.
They really are great and safer than candles too!
I think a combination works.
We love our cosy sitting room and fire during the winter months.
I also wouldn't give up my utility/back hall for anything.
A combination of spaces works.
Certainly 6 of us all in one open space ALL the time gives me the shudders.
You need plenty of soft furnishings like rugs and curtains to soften the space and absorb family noise.