GURPS Hivemiind:How do I define a walking Cottage as an advantage?

[Astromancer]

Basically, while playing around with the Character generation system and I rolled up the possession of a walking house/cabin/cottage.

How do I define a small house that moves as quickly as a walking horse and is at least as able to avoid problems as a sensible and experienced horse while being far harder to panic or spook?

Assume the house has normal amenities for a typical fantasy house in a normally anachronistic fantasy world.

Thank-you ahead of time.