In the newly constructed volume, the living room of the ADU would double as an art gallery, connected to—or closed off from—the rest of the residential wing via a pocket door. Separate entrances to the gallery and living/sleeping zones would allow private access for a future renter or caregiver, or the couple’s adult children when they visited. "The list of program functions morphed as we thought about them evolving over time," says architect Toni Lewis. "Flexibility is the key to longevity."