Daylight studies for a large scale residential development in Westminster, London. The study involved calculation of ADF values in over 300 rooms across the development. In close collaboration with the architect, multiple calculation iterations were run and the results used to further improve the daylight performance of rooms. Often simple changes such as moving balconies or windows, without changing their size, were enough to substantially improve interior daylight conditions. At the end of the iterative development process a detailed daylight performance report was produced and submitted as part of the planning application. Planning consent granted in late 2013.