Inside, three continuous flights of stair are neatly positioned at the rear edges of the site boundary to connect three floors and the rooftop terrace together. Bathrooms, toilets and storages are comfortably placed underneath those staircases. Therefore, the main functional spaces are optimized and promote a flexible photo studio on the second level and a boutique office space on the top floor. The zig-zagging staircase is designed as a 1-meter wide by 10-meter-high void space, which is amazingly bathed in sunlight thanks to the UV-protected glazing placed on the rooftop.