Text description provided by the architects. The client is a tech company that occupies an entire office building. The office building rooftop has great corner views, either to the city or to the mountains in the background. A rooftop house is built to take advantage of this as well as providing a home-like space for staff members.
Existing Conditions. The site is on the rooftop of a five-story office building with a dimension of 33mx25m in the plan. Surrounded by a 1.2-meter high parapet at the periphery, the only built structures on top is a T shaped shed that houses staircase and elevator equipment, and a series of air vents that puncture through the floor slab.
Design Strategy. To maximize the building volume and to be unnoticeable from the street level, the building mass is offset from the parapet boundary. The outer limit of the building is shaped by this restriction and locations of existing air vents.
In order to have an unobstructed view over the parapet, the entire building mass is elevated for one meter, gaining a vantage point out to the open for all activities happening inside.
The new building plan matches the T shaped shed with a U configuration. The western portion houses programs such as kitchen, dining, bar, and lounge. The eastern portion has a tea house and a living room, relatively private in terms of usage. The middle portion is comprised of service programs such as a mechanical room and a bathroom.
Four distinctive windows are placed at four corners to provide different viewing experiences to the outside sceneries. Three courtyards are introduced to create inner views as well: a tree yard to the west, a water yard to the East, and a sun yard in the middle. These courtyards bring natural elements such as light and shadow further into the house.
Structural Strategy. In order to elevate the building for one meter, a new datum is established on the existing roof structure. This new floor structure is anchored to the main beams and columns at the floor below, allowing the house structures to grow freely on this new platform.
The cavity space in-between the new floor plate and existing roof not only helps with the thermal performance of the new house but also provide depth for the earth and water features of the courtyards and space for air vents that feed into the rooms.
Building Material. The main building structure is steel, with CMU blocks as wall infill. Insulation foam panels are applied to the exterior with plaster and paint as the final finish. The interior is furnished with wood floors and plastered ceiling and walls. Due to a tight budget, the visual interests are focused on views into the courtyards and out to the landscape, rather than on exquisite materials.
