I believe that if you build something, you should use it. Otherwise no point building it in the first place. Just like in the past, people used to wrap up their new car seats with car covers. Never get to sit on the actual car seat. Only regret at time of selling or scrapping car. For me, the choices will be: If only two of us, no kids no helper, just use master bedroom toilet. The common toilet don't use the shower. Can use the WC and washbasin if needed. If two of us plus helper, use either. If two of us plus kids, we use master bedroom toilet, the kids use the common toilet. If two of us plus kids plus parents plus siblings etc., please refer to ahhboi's post.