We use the sign for house whenever we return home or re-enter the house after playing in the garden. There is a separate sign for home, but house is close enough. We also use house to refer to other homes.
We first use house to convey our home. As our babies have matured, we incorporate the idea of house as a structure where people. We sign, "walking to Grandma's house".
Get all four volumes of Baby Signing Time...