When a growing family of American ex-pats outgrew their east-end semi, they seized the rare opportunity to buy the house next door. Though tired and in need of care, it offered good bones—and the space they were craving. Working closely with the homeowners, we reimagined the layout, adding new square footage only on the third floor, where a light-filled principal suite with a dressing room and ensuite now sits above the treetops. The second floor was reworked to create two kids' bedrooms, a den, and a shared bath. On the ground floor, a new rear mudroom and powder room offer practical access for a family that parks at the back, with entry from both sides of the house. Below, the basement was lowered to make space for a guest suite, full bath, and a cozy kids’ zone. With light as a design priority (fitting for these devoted plant parents) the home is bright, open, and full of personality.