MT Terrace Medium Pair Brick 1.
It's almost impossible to take a rail journey through any of the (once) industrial areas of England, Wales and Northern Ireland without seeing the backs of streets of terraced housing (though they're very much rarer in Scotland, where tenement blocks were the norm).
Here's a typical pair, which can be made up into rows as required (the thumbnail shows two pairs together).
Many thanks to PaulSW2 for providing me with the basis for the brick texture.
The FBX/PBR main mesh is quite high in polys, though there are four levels of LOD making the use of even large groups very feasible, as they'll also share the same 2048sq texture maps.