My husband kept locking himself out of the house when he would go out to his workshop. He spends hours out there since he does the bulk of his woodworking out there, and I found it funny that he never locks himself out of the shed. He just always has that key with him no matter where he is at, but it was just near impossible to get him to carry the house key too. I finally figured out a solution when I read about a company that provides the service of locks rekeyed in Brisbane.
I had never considered having the same key for both the house and his workshop. It just seemed to me that it should be two separate keys, but then I realized that my husband probably has more money invested in his tools in his workshop than we have inventory in the house.