The Transaction Membrane is an architectural concept creating a frictionless passage in and out of a home, store, or business. Like the garage, the porch, the servants’ entrance, and the pet door, this membrane preserves the internal integrity of the building and its occupants, while allowing goods, services, energy, and information to pass through in both directions. This transfer happens without the contents being co-opted by third parties or incurring unnecessary expense of time, energy, money or material. The transaction membrane improves the lives of the people inside, as well as the environment and society outside.