Definitely lounge! We have a spare bedroom we could turn into a play room, but we’ve sectioned off half the lounge, in the corner so it isn’t walked through to get to other rooms. We’ve got main toys down here, anything extra we keep in a box elsewhere and rotate, and ‘low stimulating toys’ we keep in their room to help wind down and if they wake early (3yo and 9mo)! It’s definitely chaos in the lounge when it’s messy but so worth it x
We have a conservatory and did the lounge as it’s more suitable temperature all year. It’s just something we thought had to be done for a few years and then we can get our space back
Living room if you spend more time there. Take out any furniture not needed and put that in conservatory. It’s all temporary even if it lasts a couple of years