THE RISE OF THE THREE-DECKER

While “as Boston as a Dorchester three-decker” isn’t a saying yet, it might be by the time This Old House finishes its next project. Like baked beans and Fenway Park’s Green Monster, the housing style is a symbol of the city, and of Dorchester in particular.

The first three-deckers were built in Boston in the 1870s, during the post–Civil War construction boom. However, the origins of the style can be traced back to colonial times and the wood-building