The 3-storey house, located in Soi Sukhumvit 23, occupies a site charmingly covered with large trees and stands in contrast to huge surrounding residential buildings and a tall condominium. Both the architect and homeowner concepts agreed in wanting to keep the trees and preserve the site condition. Having such big trees in Bangkok provides a sanctuary from everyday life, and the house and garden become a secret and tranquil hideaway from the busy world next door. In order to maximize green colour space green and define serene scape, the layout of the building is then designed in an L shape not only to avoid the existing trees, but to give the home functions maximum views. The ground floor of the house is for living space, with all the main functions such as library, living, dinning and pantry designed with an open-plan concept that can be flexibly divided or combined by a moveable partition, which lets the room space flow from the front garden through to swimming pool at the back of the house, as well as allowing for ventilation. On the second floor and third floors are the four bedrooms, family room, and a special area for the owner favourite hobby, painting, which are positioned to provide an open view onto the garden. In contemporary architectural language, vertical and horizontal planes are combined in the design of this house. The vertical serves to define a space of privacy from the city environment, while the horizontal plane and the roof are designed to mimic tropical style with a high roof providing ventilation and shade. With regards to the choice of materials, the house is designed with travertine stone and bare concrete walls in the private areas, while walls of lath aluminum and glass are used in the interconnecting space to the garden outside. With the density of surrounding buildings, the designer has applied fiber cement in a new experimental proportion play with the effect of natural light, yet affording screening for the swimming pool as an architectural curtain. Delivered by the architectural concept , the design of the interior expresses the true nature of each material and enhances a spirit of local materials, such as wood, clay tiles, and exposed concrete, along with simplified Oriental ornamentation. Bare concrete walls can be seen from the foyer and main stairs, while the navigational element of the batten wood panel complements the main circulation space that fluxes with natural light. With careful lighting design, both inside and out, areas of light and their light source are chosen to emphasize a clear idea of each material and reveal its natural charm. Small interior details in every corner seem to contrast with the fine line of the overall architecture, but they are intentionally designed as places that function secretly within the simple architectural form. The whole concept of the design is then not only generated by the function of the interior, but also makes for a harmonious link between interior space and the outdoor environment. Every thought is hidden within a simple line. Every design is gradually revealed as one walks through. Every tree is successfully kept, so returning to a comfortably serene space, a Secret Garden.