The Design Process The process of designing a building is an unpredictable journey. It starts as a concept, perhaps represented as a series of sketches or some models, but as the idea develops, key considerations and decisions have to be made by the client. These will concern the use of individual spaces, the functional requirements of the building and its surroundings, the use of materials, or the heating, ventilation and lighting strategies. The decisions taken on all of these sort of issues should reinforce the initial architectural concept. During the design process it is vital that the key concept is retained and that any decision-making does not compromise the integrity of the idea. 160 PROJECT DESIGN PROCESS In keeping with the aim of creating an inclusive building, the project design attempts to bring together British technology with Yemen's rich architectural, landscape and construction traditions. Design Engine was assisted by an experienced local conservation architect who helped provide the specifications for the building's stone and mud walls and identified craftsmen who were capable of carrying out work to an exemplary standard. The building's major walls, which extend into the landscape, are constructed from Habash, a porous volcanic stone used widely in Sana'a's many historical buildings. The face of each Habash stone was hand chiselled and laid using a technique referred to as `mohanash'. Employing this technique meant that each finished face inclined outward slightly, so that at the top of each course there was a step of 3­5 mm. This subtle construction detail means that as the sun moves overhead the wall is suddenly transformed, with the courses appearing in bright relief. The building's mud walls were built using a technique particular to Sana'a. The best mud was recycled from collapsed buildings and mixed with sharp stones and straw to help bind it together. This was then laid in courses that were 500mm deep by 500mm wide, and each layer was reinforced with sticks and branches. The Yemen's local tradition of coloured glass as a building material found contemporary expression in the embassy building via a series of slot windows that animated the Corten upper façade at the building's north-east corner. The inner face of this façade was clad in oak panelling, and this language of wood and glass continued through the spine of the building providing a visual link and an illusion of connectivity across three spaces that are in fact strictly separated. The Fundamentals of Architecture Realisation