A construction set and method for assembling a Relocatable Habitat Unit (RHU) requires a plurality of flat panels that include male (M) and female (F) connectors located on their respective peripheries. The entire RHU can then be assembled using a single, hand-operated tool to engage a selected M with a selected F. First the floor is established and leveled. Next, starting at a corner, the walls are erected around the floor. Finally, the roof is created. A same, hand-operated tool is used for each task.