A departure from my predominantly Scottish buildings: a set of modules for building terraced houses, common throughout the rest of the UK but rather rarer North of the Border, where although individual units or pairs are found in many small-town streets, tenements have tended to take their place for the majority of high-density housing.
The extension modules are for the rear of the buildings: the lean-to on the nearer one is made from another of the basic units revolved through 90 degrees and with the bottom floor buried.