Marion joined PDP London in 2004, was made an Associate in 2008 and made a partner in 2015. She is currently in charge of several large high-end residential developments in central London from £120m to £2m. Her passion for sustainability and low energy design lead Marion to take part in Retrofit for the Future, which lead to the delivery of the award winning Princedale Road project, the 1st residential retrofit in the UK to be certified to PassivHaus standard. This experience lead her to write a book on 'Residential retrofits, 20 case studies' published in 2013 by the RIBA Publishing about post occupancy performance on some of the best energy retrofit projects in the country. Marion also heads the office’s ‘sustainable design group’, she sits on the board of directors of the PassivHaus Trust and is actively lecturing on the subject of energy efficient retrofits in the UK and abroad.