A lot of the homes in our Capitol Hill neighborhood have a rear ell. I have been interested in the rear ell’s for a long time.
For one, I thought, initially, that the ells were all built as part of making an addition without underpinning the neighbor’s building where the neighbor had the “first mover’s advantage” of not having to worry about undermining an existing structure.
But over time as I became more interested and looked a lot closer I began to see that so many were built at the same time as the original structures. This article helps to explain the purpose of the original ells.