I think that mother in law suite additions can add more value to the home. I especially like the idea of a home and a cottage on the grounds.
This not only offers a certain level of autonomy and privacy for the elderly parent but it can also provide investment income when the elderly parent moves on to an assisted living facility or a nursing home.
It also is a great selling feature that you have an additional income property on the premises. If you are looking into house design plans this can be a nice feature.
Also, your children can join you and stay in the guest home if they like and it really allows for more guests to stay at your home.
This would be especially beautiful if you had a coastal home. A coastal home design adds another layer of beauty and tranquility that would be lovely to share with others.