The New York City-based firm Delson or Sherman Architects assembled this duplex apartment in a Soho row house from two stacked apartments and a new rear extension. Their clients were a single mother and her daughter. "The rooms in our design begin compressed, then sequentially expand to draw you through the space," says principal architect Jeff Sherman (whose own amazing apartment we'll be spotlighting in a future issue—stay tuned!). To gain ceiling height in the back, Sherman lowered the extension’s floor, creating multiple levels for gardens: a green roof off the master bedroom, an arboreal backyard, and a sunken terrace outside the living room. Here, he takes us on a tour.