A laundry room. With space to hang all the laundry up not just wash it.
A utility cupboard to store vacuum cleaner, broom, mop etc.
A cloakroom so that there is ample storage for all the coats, shoes, bags, hats etc instead of them being crammed into a cupboard in the downstairs loo.
A big cupboard in the kitchen for the air fryer, instant pot, breadmaker etc (need a bigger kitchen to fit this cupboard in)
So basically better storage.