Without mortgages, most people in colonial cities did not own their own homes (perhaps fewer than 10% at the time of the revolution). The greatest demand for rental housing was for small houses for the poor and working classes who couldn't afford to even rent large houses, or afford the fuel to heat them. In the early 18th century, these houses were often made of wood (see the workman's house behind the Todd house) but by the end of the 18th century and the early 19th century another typology had emerged - the trinity.
Bell's Court
These early 19th Century trinities are one of the few surviving examples of a row of these type of houses.
These four trinities of Bell's court are the best example of a row of trinities built during the speculative housing boom of the turn of the century. They face a common area which was originally a private alley. Built in 1813 at the transition between the Federal and Greek revival styles, their less affluent target audience means they are devoid of almost all decoration (there is small brick dentil work at the cornice) but are not unlike the more traditional small row houses of Elfreth's alley. The entrances are also very plain, lacking any elaborate lintels or decoration on the jambs, but there are tiny transom windows. Trinities stayed in fashion for a simple, cheap housing solution to the time of the Civil war.
As its name suggests, the trinity is three single rooms, stacked one on top of another, and a basement for storage, and sometimes cooking. An enclosed spiral stair connected the floors. The cooking fireplace and a second fireplace on the ground floor could heat the whole house but heat could also be kept on the ground floor through a door on the winding stair. The trinity could be built free standing or in rows to increase construction efficiency and reduce heating losses.