Eric has worked for years to develop a system of homebuilding that can be expanded in a modular fashion. It begins with the core house, and then expands with wings and "knuckles," allowing a proven set of house pieces to be built over time in countless ways according to site conditions.
Eric has for years been running a veritable laboratory for constructing houses better. Some of those advances were about the construction systems themselves, such as letting houses breathe in hot and humid climates, and carving into wall cavities to keep them dry and to recover the space. Eric has a great rant on the fact that we're only building cartoons of traditional buildings because they can't open up and breathe like the homes they're intended to resemble. Instead, we've "wrapped them up so tight that they must be put on mechanical life support.”
The Evolution Cottages, however, are about the ways we put large parts of houses together. Much of the lovability of early American architecture had to do with the fact that the buildings were added onto incrementally across several generations. Even Thomas Jefferson built this way, living in one of the little cottages behind Monticello for nine years while he built the main house. Eric has systematized this idea with the Evolution Cottages, making it easy to build small now and grow later.