Would be fun kid hideout space! Awesome dog kennel under the stairs design idea. If you want an indoor dog house, utilizing the space under the stairs for a cozy, attractive and practical space for dogs is a good idea! I love this design.
~This is so hardcore me. I'm a socially awkward dragon only interested in books and fictional world escapism.~<<I'd probably do this, but the people in my life would just assume it's me being intentionally sarcastic/annoying.