structural and finishing costs in yemen

CIB2007-415

Structural and Finishing Costs in Yemen

technologies and materials nd are relatively costly. Cost reductions can be achieved in practically all

d to provide a breakdown of construction costs of structural and finishing elements. Proposals are made to contain construction costs in Yemen.

KEYWORDS: Structural Costs, Finishing Costs, Construction Materials, Yemen and Developing Countries.

Sultan Basel

ABSTRACT

Construction cost is a key factor in the choice of methods and materials in any construction project. The trend towards modernization in Yemen has caused an ongoing shift from traditional to modern buildings. These modern buildings depend mostly on imported acases only by lowering of quality, consequently creating less attractive and less durable buildings. After providing an overview of the construction industry in Yemen, a local survey was conducte

3116 CIB World Building Congress 2007

his tendency to reduce the overall construction cost has only

led to over-designs, excessive use of construction materials and site waste, unnecessary structural members and concurrently an increase in construction cost in the modern buildings. As well, there are inadequacies in designs, which designed inappropriately and not in accordance to the local needs or priorities, absence in project management and supervision

1 INTRODUCTION

Like other developing countries, the construction and the material industries in Yemen are undeveloped, and failed to meet demand. The widening gap between construction needs and the domestic materials production has inevitability led to increased import dependence. According Edmonds (1979) the construction industries in developing countries are heavily dependent on imports of materials, which account for 50-60 % of the cost of the construction output. Miles (1984) pointed at the problem of the heavy reliance of the construction industry in Yemen on imports, as materials comprised 60 to 70 percent of the construction costs in the modern sector in Yemen. Historically Yemen has established a unique building tradition this rich, characteristic and uniform style of the traditional Yemeni architecture and townscape justifiably admired. Until few years ago, this tradition had being successfully sustained. The emerging trend of modernization and urgent need for infrastructure and housing project in Yemen has caused an ongoing shift from the traditional to the modern building types. These modern buildings depend mostly on imported technologies and materials, which generally considered costly. Recent history, has demonstrated that it was not possible for the local construction industry to adapt and develop their marketable, managerial and technical skills sufficiently to cope with the rapid growth and vast demand in these modern forms of construction that have been occurring over these last decades. Sultan & Kajewski (2003) indicated that some of the specific difficulties associated with the Yemen’s construction industry are the unclear and none unified construction technologies and methods, as well the tendency of the clients/owners to minimize their construction costs by eliminating or minimizing the technical and engineering assistance in design and supervision. T

CIB World Building Congress 2007 3117

rly as less important are labour cost and availability. Ironically, the participants think that local materials and construction technical problems are

A report by Tassios (1992) for the United Nations Industrial

iew of that suggests some solutions that could improve the situation and approach justifiable cost and quality.

2 TRADITIONAL CONSTRUCTION AND MATERIALS IN YEMEN

Unlike other countries in the region, the Yemen has a unique heritage of buildings, urban centres and civil construction (Serageldin, 1982). Few decades back Yemenis utilized only locally available materials to fuse from and function in their creations. The characteristics of the traditional construction in Yemen are the use of local materials and the implementation of indigenous methods and techniques (Figures 1 & 2). The buildings may have as many as eight storeys and they have load-bearing

potentials and practices, what’s more the lack of any approved national system of codes, standards or models have only complicated the industry’s problems. A survey by Sultan & Kajewski (2004) indicated that the most important factors causing high construction costs were identified as imported materials and construction waste. Factors that emerged clea

insignificant.

Development Organisation (UNIDO), indicated that the ratio ( λ ) of structural components cost to the finishing components cost, seems to reflect the level of construction development. It was found that in some African countries the ratio was 1:1; in rapidly developing areas such as Greece λ was 1:2 and developed countries λ was 1:4. Although the role of the modern imported building technologies and materials to the national economy still to be questioned, the main concern of the paper is to approach some improvement in the current construction activities. Initially this paper reviews in brief the historical background, transformation phases and the local conditions and difficulties associated with the construction industry in Yemen. Subsequently the paper uses the ratio (λ) primary to pursue that the structural components are the major contributors to the overall construction cost and on the account of the finishing components’ quality, in v


walls constructed with either exposed hewn stone or rammed earth or earth-blocks, depending on the material available in the region. There was an elementary but effective organization for construction. The compelling merits of this traditional model of the construction industry, which survived with almost no change over centuries, were many. Designs were such as to meet the needs of the environment not to violate it (UNIDO/World Bank Cooperative Programme (1981).

Figure 1


Figure 2

Those structures built with the traditional construction methods and materials used to give very satisfactory results. The traditional Yemeni architecture is well adjusted to the hardship of the different climatic regions of the country. In dry climates with big differences in temperature between day and night, houses built with stone, brick or mud walls of thickness of 50cm and over. This is particularly important because of its excellent thermal insulation qualities, walls reduce the differences in temperature of the interior spaces to the minimum, in an area of temperature extremes between night and day. Traditional materials for the mountain area are natural stones; various natural stones are used for foundations and exterior walls. Burnt clay bricks are also used for exterior walls, mud bricks used for interior walls. Timber

nd branches used for roofing, doors, window and frames. Hardware aTraditional buildings is made locally. Gy

in psum is used as plaster for walls,


inning to offer some competitive products. In hot and humid areas, the traditional buildings have high ceilings

ventilation. The traditional materials for these coastal region are burnt clay bricks and mud bricks, while natural stone,

,

3 TRANSITION PHASE

ceilings, and floors, as well as for decorative arches over windows and doors. Hand dressed stone is still the common material on the plateau, but mechanical methods of quarrying and cutting are gradually being introduced because of the current high cost and low productivity of labour. The introduction of electric saws to cut the stone and thus reduce the labour factor has not met with unqualified success, because the resulting flat and even surface is far less attractive than rough-hewn surface. Traditionally, bricks are still made by hand, but mechanised brick factories using the latest automatic firing and handling equipment are beg

and large openings for cross

which is so commonly seen in other parts of the country, is generally not there or very little. Mud is a traditional material used for walls, floors, roofs, with various techniques reflecting the local skills, climate and availability of materials. Its use has decreased in the urban areas. Mud buildings in all dwellings fell, an indication of greater desirability of cement-based buildings. Though, cheap mud walls are considered unattractive, subject to water penetrationnot durable, and if not well constructed, may not be structurally sound. Local and traditional walling materials are currently not widely used in most parts of Yemen; the obvious reasons were the public’s ignorance of the material, lack of interest from clients and designers, inadequate government support, poor publicity and non-existence of building regulations that encourage their use. Moreover, the widespread use of Local materials is hindered by the limited quantity, poor quality, and high cost. The craftsmanship that marked traditional Yemeni stone and brick construction, is rapidly disappearing (Serageldin, 1982). The traditional dressed stone and bricks are now being widely replaced by cement blocks. Some of the unique heritage of Yemeni architecture is being lost.


ecting Sana’a with Hodeidah. There was no

stitutional framework, insignificant administrative culture, and almost no technical and managerial cadres, it was impossible for the new government to control and channel this sudden inrush of

construction rapidly outpaced the limited resources of the technical and

rivate owners was inadequate to meet the demand for construction. By at increased were the prices of these materials with deteriorated quality (Kulkarni, 1983). The demand for new materials shot up, and each consultant specified only the products with which he was familiar. This created a scramble of imports. The coordination of import policies required for the construction industry was lost in the chaos and mess. Whatever material was loaded at the port was used up. It was difficult to specify construction products and then receive them in sufficient quantity. Followed the import of new materials came the introduction of new techniques of construction, new equipments, and new skills from outside the country. A new breed of technicians and works flowed into Yemen,

Prior the 1962 revolution and during the civil war that extended up to the 1970, all the public sector construction was the direct responsibility of the ministry of public works (MPW). Before 1962 the only paved road in the country was the one connelectricity, water, sewage or other municipal services, no schools, and no hospitals. Thus, the government was faced with the massive task of developing from scratch tremendous task of nation building (Miles 1984). The new government invited many international organizations and humanitarian agencies to assist in its socio-economic development. Funds and experts poured into the country during the transition period from 1973-1981. With the old in

developmental assistance. The funds that became available for

administration staffs of the MPW. The limitation of the Ministry of Public Works and the concern of other new ministries and authorities to provide infrastructure and rapidly achieve physical goals created a ‘free for all” situation. Every department of the government involved itself in the construction industry. Under the pressures of the expanding assistance and credits, they lost sight of the need for coordination of efforts. The impact of planned development in the Yemen was felt in the building materials sector of the construction industry. In 1973, the rate at which the materials produced by p

1976 all th


while the local traditions were pushed into the background. The traditional

The modern construction refers to buildings that built recently in Yemen, mostly in cities and towns. In these urban areas, constructions are frequently carried out using modern techniques, and whose main characteristic is the structural reinforced concrete frame. The walls are made of cement blocks, local stones (figures 3 & 4) or cement blocks with an additional external facing of local stone to simulate the traditional style, a kind of modern/traditional, which is expensive. Individuals who can afford a stone construction still prefer it to the cement block, in terms of less maintenance and good insulation.

Figure 3

Yemeni knowledge, experience, and insight regarding local materials started to disappear quickly. The construction industry lost its character as a craft-based industry.

4 MODERN CONSTRUCTION IN YEMEN


The exterior walls of high-income housing structural reinforced concrete frame are usually constructed in stone masonry, and this work is executed with great skill by local masons. The architectural appearance of houses is most appealing, and thermal comfort is good. Nevertheless, the costs of labour and excessive material are high.

Figure 4

Buildings designed and constructed in the “modern” technique, where walls are made of cement blocks only, they are usually plastered inside and out side with cement plaster, are usually unsuitable to the various climatic conditions of Yemen. Their design often ignores the regional environmental conditions. Consequently, there is no adequate protection against the climate, and comfort is minimal. The reinforced concrete buildings with concrete block walls do not have enough thermal inertia. Hence, they are warm during the day and cold during the night. The stress caused by the extreme differences in temperatures very quickly deteriorates the construction and the appearance of the building. Buildings of the same design that are constructed in the coastal hot climate of Aden


and Hodeida offer very little thermal comfort. Concrete and plaster disintegrate very quickly under the humidity and salinity of the air (figure 5).

Figure 5 However, due to the generally low productivity, most major projects have eliminated stone as load bearing material, although stone remains popular as a facing to reinforced concrete frame structures. As the cut stone and decorated brick facades have become too time consuming and too costly to build. The modern style is gaining ground primarily under the momentum of the technology (roof spaces, speed of construction 42 weeks against 85-95 weeks) and economics, not personal taste (Serageldin, 1982). Materials that have been introduced in recent times are hollow cement blocks for walls, reinforced concrete slabs to replace traditional roofing and flooring materials, reinforcement steel bars and structural steel, and terrazzo and cement floor tiles. The following materials are imported in the finished form: cement (other than ordinary Portland), steel sections,


ctrical fittings, ironmongery, glass, aluminium, mechanical equipment, and bitumen. Wood, once obtained from Yemen’s

g materials industry in which the government is

by volume, In ther cases, concrete is mixed by hand. Quality concrete of specified

strength is not frequently produced by these methods due to that the operation is not properly supervised. In major projects, all complex mechanical and electrical equipments are imported and expatriate technicians must be employed. Even after

sanitary appliances, ele

now depleted forests, is mostly imported. The manufacture of doors and windows is done locally in small workshops. Materials that are manufactured locally in Yemen from imported raw materials include ordinary Portland cement, aluminium items, and galvanised iron sheets, paints, plastics pipes, PVC conduit, nails and screws. Wholly local items include stone and aggregates. The only major buildininvolved is cement. The government has urged the private sector to be a major investor in the expansion programmes. Ordinary Portland cement is now the most important constructional material in Yemen. Cement produced by five factories, Most are financed from local private sources, sometimes with foreign participation. Plants are located with fairly adequate geographical distribution in land and along the coast. Nevertheless, frequent shortage of cement has constrained the output of construction industry, and the already high price of cement has increased three-folds between 2001 and 2006. All reinforcement steel is imported. The only Potential savings that has occurred was when mild steel was replaced with high tensile steel to obtain the same structural capacity as concrete reinforcement, hence reduced labour and shipping costs, this was an offset against the higher unit construction cost. Most of the structures before designed by local engineers had used the readily available mild steel. On the small projects (the majority), cutting and bending steel is generally done manually using hand tools and simple equipment. Most contractors set up reinforcement fabrication yard on the site, as there is no specialist steel stockholder, who will cut, bend, fabricate and deliver reinforcements cages. On small sites concrete is mostly mixed in 1/4m3 drum mixers with bachingo


commissioning p operational and maintenance schedules. In medium and small projects, the

stallations are less comple ny c be ured ractor normally employs a local

d sub-contractor for the tallation, and the later is usually able ith local designs and m ls.

he chaos and the loss of identity and the rapid transfer to modern chnolo

ost of materials. ccording to Sultan & Kajewski (2004), the high construction costs are

ite of the high imported material , .

estimated as 1:0.87,

, expatriate advice is often required to set u

infrom local merchants. A general cont

x, and ma omponents can proc

specialiseto work w

insteriaa

5 LOCAL SURVEY

Tte gy within the pressing and crucial need for infrastructure and housing projects and lack of research has led to the incapability to monitor, control nor to recognize the faults, weakness and limitations within the construction process, all coupled with the rising cAalways coupled with low quality of finishing in most modern domestic construction projects. since the aim of this paper is to pursue that the construction components and activities within the structural process has the greater share in causing unnecessary construction costs and distressing the quality of the finishing components. A survey was conducted to examine the distribution (breakdown) of construction costs contained within the structural and finishing elements in the modern construction projects. 49 respondents were asked to give their cost distribution of the structural and

g elementfinishin s as experienced in the local market. The responses were calculated and summarised in table 1, together with the breakdown and

ed value of cost by elements of building as averag it occurred in some developing and in the developed countries. It was found that structural elements in Yemen on average have consumed approximately 53% of the overall construction cost, and in spcontents and costs, the finishing elements consumed the remaining 47%Table 1 also shows that ratio (λ) for Yemen, which is which gives an indication to the high costs in the structural components in


untries. Therefore it can be confirmed that the structural elements are the main contributors to the construction cost

Table 1 Breakdown of Cost by Elements of Building

cost in

(basalt) load bearing

• Unplanned and inefficient production and distribution allocation of stones causing unnecessary increase in cost

comparison to the developed co

and on the account of the finishing quality. Hence the initial attention for improvement is required first within the structural elements.

Structural (%)

Finishes and equipment

(%) (λ)

Senegal 49 51 1 : 1.04 Ghana 53.5 46.5 1 : 0.86 Kenya 63.2 36.8 1 : 0.58 Yemen * 53.1 46.9 1 : 0.87

Sources: Tassios 1992 and *Local Survey As extracted from previous research papers and as stated by the survey participants, some of the main reasons for the exaggerated

Developed countries 20 80 1 : 4

the structural components and activities are, as follows:

• The absence of local standards, specifications and lack of knowledge on local and imported materials

• Unclear construction practices/methods. and mixing traditional and imported building technologies has created unnecessary structural elements, such as combining black stonefootings and walls, with the R.C. foundations, ground beams and columns

• Excessive waste and inefficient use in the external stone walls and facades


s

and cement

• Enhance clients’ and designers’ knowledge and interest towards so they appropriately and widely used, through

support and good publicity of building

• The tendency to waste expensive materials in low-performance uses, such as the inefficient use of Portland cement in masonry work

• The tendency to eliminate engineering services and supervision • The over-design practices, which are due to:

o the use of high safety factor designs due to the lack of trust against unknown quality of structural elements such as steel

o the elimination of soil testing.

6 RECOMMENDATIONS

Having reviewed the local conditions and background of the construction and material sectors in Yemen, the following recommendations can be suggested:

• There is a need for changed or improved construction methods, and efficient designs that effectively make use of local resources, additionally sustain some traditional character. To approach this, there is a need to recognise the incomes, history, culture, aspiration, priorities and local resources, for creating acceptable local construction methods and models. Only schemes making the best use of local values, culture, customs, building traditions and cooperative devices had a chance of success.

• Reduce construction waste by using appropriate and clear construction technology improved practices and specifications. Moreover, rationalize the tendency to waste expensive industrial high performance materials, in low-performance uses. Accordingly, this should reduce the frequent market shortage. Improvements in supervision activities and supervisors training are required.

local materialsadequate government


f such materials also by changing designers and users

tal conditions.

• There is a need for well-organized utilization of available stones s in Yemen, retain large quantities of sedimentary

rocks are available in a wide range, types and colours). The use of ade

essary c requirements and feasibility of the main structural

ed the

regulations and codes that encourage their use. Encourage the use oattitudes towards them. Equally, motivate the public’s confidence by strict control on the quality of materials.

• An extensive study should be should be done into the local materials for their appropriate and extensive use. The selection of materials should be based on technical suitability, economic feasibility and social acceptability.

• For better allocation of resources, there is a need for a planned and efficient production, distribution, it is necessary to categorise the

• type of construction projects based on the area and regions in which the materials should be used. The Distribution and access of stone materials to any region should be in accordance to the material suitability and resistance to the local environmen

(several region

load bearing stone walls and facades for dwellings may be messential.

• Manage the importation of materials, according to rational trends of material demand and the ability of the economy to support such imports. Hence, a survey is required to study the total necdomestimaterials such as cement and steel reinforcement.

• Develop applicable monetary and fiscal policies that can initiate technical and economic construction development (Sultan &

e Kajewski, 2005), to control market prices; hence affect thselection in accordance to the local availability and suitability.

lar and • Develop construction regulations that can reduce irreguunacceptable activities, and facilitate any newly improvconstruction practices. Moreover, control the quality of


quired

se y. or le

y

components and activities in construction projects is relatively high. It suggested that any approach to improve the situation should initially unravel the problems associated with the structural components. Such as the problems associated with the inadequate designs, inadequate use of building materials or the inappropriate choice of materials that is not in accordance to the local needs or priorities. As well as creating clear building technologies, national system of codes, standards and building models that recognise the history, culture, incomes, aspiration, priorities and local resources and environment of the region. Development to the structural components would concurrently lead to the quality enrichment in the finishing components.

construction materials that should boost the designers’ to confidence to generate more proper and acceptable designs.

• There is most of all an urge for institutional, administrative, and human development to assist and monitor any redevelopment (Sultan & Kajewski, 2005).

7 CONCLUSION

The pressing need for infrastructures and housings projects and thestyemerging trend of modernization in Yemen has caused an ongoing, ha

s. Theand careless shift from the traditional to the modern building typemodern buildings considered relatively costly with poor finishing qualitNoticeably during the last three decades, there were hardly any focused persistent efforts by construction industry in Yemen to achieve reasonabdevelopment. The construction development in Yemen is assessed in this paper blooking into the construction costs contained by the structural and finishing works. It was found that, the cost of structural


8 REFERENCES

Edmonds, G. A. (ILO) (1979), The construction industry in developing countries, International Labour Review, 118, (3), 1979, 355-369 Kulkarni, B. V. (1983), A Construction Industry in Transition. Development and Urban Metamorphosis; Volume 1: Yemen at the Cross-Roads. Evin,

Ahmet (ed). Singapore: Concept Media/The Aga Khan Award for Architecture. Miles D. (1984), Yemen Arab Republic: the construction industry. HUDevelopment and Urban Metamorphosis. Volume 2: Background Papers UH, Editor Ahmet Evin, The Aga Khan Award for Architecture (1984) Serageldin Ismail. (1982), Rural Architecture in the Yemen Arab Republic: The Impact of Rapid Economic Growth on Traditional Expression. The Changing Rural Habitat; Volume I: Case Studies. Brian Brace Taylor (ed). Singapore: Concept Media, The Aga Khan Award for Architecture Sultan, Basel and Kajewski, Stephen (2003), The Yemen Construction Industry: Readying the Industry for the Successful Implementation of Sustainability, paper for the CIB 2003 International Conference on Smart and Sustainable Built Environment (SASBE2003) 19th- 21st November 2003, Brisbane, Australia Sultan, Basel and Kajewski, Stephen (2004), Local Problems in the Construction Industry of Yemen, paper for the CIB 2004 Working Commission W107 Construction in Developing Economies, International Symposium on Globalization and Construction W107 Construction in Developing Economies With participation by TG23 Culture in Construction, November 17-19, 2004 Bangkok, Thailand Sultan, Basel and Kajewski, Stephen (2005), Policies for Economic Sustainability for the Construction Industry in Yemen, paper for the 3rd CIB Student Chapters International Symposium, 4-8 July 2005 8 July 2005, Queensland University of Technology, Brisbane, Australia Tassios, S. (1992), Structure & function of the construction industry with emphasis on developing countries. Paper ID/WG.528/1, 8 September 1992, prepared for the meeting of UNIDO and UNCHS (Habitat), First Consultation on the Construction industry, 3-7 May 1993, Tunis, Tunisia United Nations Industrial Development Organization UNIDO/World Bank


Cooperative Programme (1981), Yemen Arab Republic: The Construction Industry, Report no. 17, Vienna, July 1981.


structural and finishing costs in yemen

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