The design was singled out by judges for blending innovative design with thoughtfully designed landscape that homes in on a small serpentine lake and water features.
The development by St Edward Homes in Harrow, London, shrouds 800 apartments and office space in a sinuous landscape designed by fabric.
Director Andrew Smith said: "I am happy Stanmore Place has been acknowledged as an example of outstanding landscape design."
The ongoing development, started three years ago, is reached by a bridge over the lake with over a thousand fresh-water fish. The landscape includes cycle paths and a children’s play area.
Latest phase includes further planting and apartments with balconies and terraces overlooking the water and central courtyard gardens.
St Edward Managing Director Paul Vallone said: "Stanmore Place is being recognised for its remarkable landscape design, testament to the fact that at the point of its third anniversary, the development continues to thrive."