arba- as in the French word arbalétrier, a rafter, a key element in a wood frame. It supports the roof and withstands wind, rain, and snow loads. It is also, as in arbalète which is the French word for a crossbow. An instrument consisting of a bow mounted on a stock that shoots projectiles. It might also be as in arba’a the Arabic word for the number four, an echo of the first question at the beginning of a project: How to choose the best orientation among the four cardinal points? arba- is a young architecture studio established in Paris since 2007 by two architects : Jean Baptiste Barache and Sihem Lamine. arba- is dedicated to developing new housing solutions aiming at sustainability, affordability and interaction with the natural and the built environment. arba- designs houses as functional, smooth, simple and optimal pieces. Their main purpose, ‘to serve as a dwelling’, is not separable from a second purpose: ‘allow to see through’. Such houses relate more to instruments than to buildings. As with musical instruments, lines and shapes are pure and minimal while allowing for a broad range of potential uses. The dweller is naturally involved in a game of uses and interactions with the garden, the neighbourhood, the landscape, the sun, the light...