A dogtrot house is a type of house that used to be found in the rural South. It consists of a covered breezeway (the "dogtrot") in the center with a single room on either side (typically one side served as the bedroom and the other side as the kitchen/common area). From the landlord's point-of-view, the nice thing about a dogtrot house was that it was simple, quick and cheap to build.
Pictures of a dogtrot house are at:
www.chadwickartphotography.com/dogtrot_house.html
www.chadwickartphotography.com/crepe_myrtle_and_dogtrot_house.html
www.chadwickartphotography.com/dogtrot_house_side_door.html