I don’t think the entrance area/wardrobe is well designed. Where do the jackets, shoes, school bags, MaxiCosi, strollers go in winter? Where do you want to help the children put on their shoes, etc.?
In the kitchen, I would miss the workspace. Living/dining/cooking feels tight to me. The playroom doesn’t work – at least I have never experienced it working.
Where should the laundry be done? Surely not in the room with shoes, sand, and dirt. Sand cannot be avoided anyway. What do you think, how often will you have to wash hair if hair washing is done after playing with sand? Storage space is missing. Especially if two more children come. Clothes, toys, vehicle fleet, strollers, etc. are all kept, plus Christmas decorations, etc.
A bathtub is missing. Ever had kids soaked in the autumn mud or thawed out after sledding? In the competition of who gets the dirtiest, even underwear does not stay mud-free. This Ikea setup won’t last long. Besides, eventually, you want to get into the tub yourself. Warm baths can do good.
Air space is gone. Your house will be loud. You don’t want to facilitate sound transmission any further.