Chapter 4, page 121 ATTITUDES AND PROCEDURES CHAPTER 4- THE ART OF BUILDING Section 1 -Attitudes and Procedures The farmer is also a builder and the ability to construct appears as part of everybody's natural experience, as it was vividly illustrated to the writer when he saw children playing at "house building" with miniature mud blocks made by themselves at Wadi Dahr. The tools required for building operations are small and simple: wood forms and paddles for earth construction, hammers, chisels and steel squares for stone masons and carpenters, floats and knives for plasterers and plaster carvers. Scaffolding is not erected; workers use the stair which grows with the building and the tops of the walls to circulate. If decoration or repair work needs to be done on the walls the artisans work from ladders or platforms suspended by ropes from an upper level supported by the muscular strength of helpers. The emphasis throughout is on intensive human participation. The overall process appears to be guided by constructional directness and economy of resources. A case in point is the frequent setting of door and window frames as the wall is built so that not only the perfect fit between jamb and wall is immediately ensured, but also a base is provided with the door or window head to support the formwork for the arches above. Similarly, metal grills for windows, pre-cut as a semi circle at the top, may be used for the same purpose. Methods appear also to comprehend a degree of risk and carefree casualness. Looking at certain construction details one might say that the principle is "if it holds it is sound", such as when a floor landing is seen supported by the apparently frail arcade of a parapet. Likewise the surroundings of an opening may be whitened by merely splashing plaster from the inside as far as the arm can reach. Rooflines may be left "unfinished", suggesting that the building is to continue or else that it should have continued a long time ago and that its stopping at that point was just the same as having it finished. "Serendipity" would be a good word to describe how the formal inventiveness of the buildings is often left to accident. This is apparent in forms relying on natural characteristics for their existence but also when solutions are found that profit from the natural shape or fortuitous positioning of the materials. For instance tree trunks are used for roof joists as twisted as they come; the natural result is the highly sculptural Chapter 4, page 122 ADMINISTRATIVE PROCEDURES quality of many ceilings. Yet it is also true that design as a statement of purpose plays an important part in the formal language of building in Yemen. Hence the concurrent appearance of adapted accidents and strict proportional and geometrical principles not only in the shaping of particular elements but also in the whole volume of the building. Building in pre-industrial Yemen had little dependence on administrative procedures. In the villages, building involved authority from the village head or shaykh; in the towns, permission to purchase land and build on it was needed from the neighbourhood chief (amin al hara ). Farmers built their houses with the help of their family and neighbours; tribesmen assisted in the erection of their shaykh's house. Outside help was called in for specialized details such as wood or plaster carving and, more recently, plumbing and electric wiring. In the urban context the construction of the house was entrusted to professionals, involving a wide range of craftsmen, organized in guilds with varying degrees of prestige, the passage from one guild to another being difficult. Responsibility for the whole building remains with the 'usta - the chief mason and contractor. He works for the owner of the building either on a weekly wage basis (ujra ) for himself and his workers, or as a contractor (muqawil), for a lump sum. The title of 'usta, the highest in the hierarchy, is not always hereditary and, to obtain it, the patronage of a qualified usta is required as well as practical experience. Several years are spent by a young mason (tilmidh ) under the guidance and name of his master (muallim.), who may be a parent or patron, until he can work independently and be allowed to engrave his name on a building. To have a house built, the owner approaches the usta and tells him the kind of house he wants, perhaps using as reference another house by the same mason or that of a neighbour. The usta then marks out the floor plan on the ground and explains how the rest of the house is to be developed. Adjustments are then made and after obtaining the owner's approval, the building proceeds to the first floor. Thereafter the same procedure is repeated at each subsequent level. Stones are purchased at the quarry and brick at the kilns by an intermediary who delivers them either to the owner or the usta, if he is the contractor. The mud for earth buildings - whether in coursed clay or in blocks - is usually produced at the construction site but, in the 'seventies, places were still frequently seen where mud blocks were manufactured to be sold to other construction sites. Chapter 4, page 123 REGIONAL STYLES Section 2 - Materials and Techniques 2.1 - Regional styles Except for vegetal fibres, used exclusively in the Tihama, the traditional materials of Yemen are raw or baked earth and stone, for the wall structure; mud, lime and gypsum plaster for rendering of exteriors and interiors; wood, alabaster and coloured glass for wall openings, and iron or brass for fittings. Glazed clay, seen in Tihama pottery, is not used in traditional construction: the only glazed tiles the writer saw were imported and recently applied. The material of which the building is made, normally that which is available in situ, does not influence the basic plan of the house types surveyed, but establishes variations in style reflecting the physical landscape and surface geology. Thus, earth construction is predominant in areas with alluvial deposits, stone construction in the rocky slopes. Mixed situations frequently occur, either in the same settlement or in the same building. Towns usually display the more refined examples and those that fall within the availability of several materials, as at Sana'a, Dhamar, and to a certain extent, Rada', offer a synthesis of the use of different techniques. House extensions uninhibitedly carried out in different materials and styles are frequently seen, particularly in the post-Revolution period. For example an original dwelling in mud may have been improved by a new cut stone extension with windows of a different regional origin. Similarly a brick floor may be added to a stone building. New materials, once they became cheaper and quicker to apply, made understanding the history of a house more obvious. In much of the countryside stone and earth now cohabit with cement blocks and corrugated metal. With the exception of the Tihama grass houses, foundations and roofs are always constructed along similar principles and there are only minor technical variations in the way each wall material is used structurally. The textural differences, however, justify the drawing of a tentative map of regional styles based on the material of the structure as much as on the treatment given to surfaces and fenestration. The homogeneous groups mapped by the writer are named after the town or wider area where they were seen to be well represented. However, there may be better examples and additional subgroups may be found in areas that were impossible to visit at the time of the survey. Chapter 4, page 124 FOUNDATIONS, FLOORS AND ROOFS 2.1 - Foundations, floors and roofs All buildings have a hard rock foundation, commonly of cyclopean stone often from wadi boulders. With ease of transport after the Revolution the use of basalt became widespread and extended to areas where it had not formerly been part of the local building tradition. A basalt plinth, two or three courses above the ground, has become a feature of stone buildings over the 20 years covered by this study. Foundations are dug until solid ground is reached, the rule being that of "until the soil is too hard for the pick to enter". This accounts for foundations being 2 or 3 metres deep in alluvial soils and very shallow in rocky areas. The foundation may not be apparent, as is common in much of the earth construction, or it may be raised to form part of the ground floor walling. In this way when the top floors are of earth, the ground floor may appear as a high stone foundation. Stone foundations continued to be used after the introduction of framed concrete structures with the concrete foundation beam bearing on the cyclopean stone. Floors and roofs are built by providing a load bearing structure of parallel beams - very often just rough tree trunks - at 40 to 60 cm centres. In the Mountains, twigs are then spread between and covered with a thick (around 30 cm) layer of sifted, dampened and compacted earth. This may be left exposed or covered with a coarse aggregate or surfaced with water resistant lime mortar (qadad ). Waterproofing the roof with qadad may be explained, as at Ibb , by the amount of rainfall in the area but also improved finishing as was seen in the much drier northern Highlands. On the ceiling side the twigs are surfaced with a mortar made of mud and dung (malaj ), which, in all but the most remote or elementary buildings, is finished with the same gypsum plaster used for the walls.