Building Disaster and Failures in Nigeria Construction Industry: A Case Study of Some Cities in Osun State

Despite the efforts to improve the quality of construction works through use of advanced technology, increased labor force for professionals in the construction industry, increased availability of construction equipment, there is still low quality work. Building failures result into economic and temporal deviations in construction industry. The purpose of this research is to develop strategies to mitigate building failures in the construction industry in Nigeria. Descriptive survey research design was adopted for this research in some selected urban cities in Osun State. The study population comprised of 210 respondents: Supervising engineers, Site engineers, Site foremen, Clerk of works and Clients. Causes of building failures were categorized as: consultant related; contractor related, construction related, client related and external related factors. The data collected were analyzed using correlation and regression analysis with SPSS.. Findings were presented using descriptive charts and tables. The findings indicated that Inadequate supervision of works (RII= 0.79); Shortage of equipment and materials (RII=0.76); Cash flow problems (RII=0.67) and Inflation in prices (RII=0.70) were the leading causes of building failure in their respective categories. Based on study findings, it was concluded that there is a great influence of consultant related factors on the causes of building failures more particularly related with inadequate supervision of projects. Defects result from non-conformance to requirements and always result in rework. The overall causes of defects can be attributed to design, construction, material and subsurface conditions. Finally, the causes of defects lie in inadequate management or inadequate technical skills. The descriptive analysis clearly indicates that construction-related causes dominates.


Improper Selection of Materials
In construction industry many types of materials used are from man-made to naturally available materials such as timber, steel, plastic, brick, mortar, glass, etc. Most of the times these materials are used without any test or checks to determine whether these materials is fulfil the standard specifications or not [2] and [6]. According to [7], substandard materials especially reinforcement rods, steel sections and cement can contribute immensely to failure of buildings. Functionality in the operating environment is generally a high priority for material selection of components, especially when it comes to the long-and short-term safety and reliability of the equipment.

UnSkilled Manpower
Most contractors working in the construction industry are beginners with low levels of construction skills and capacity to discharge their duties [2] and [4]. In most cases, local contractors who acquire construction contracts hire low skilled laborers who in turn demand less pays for labor costs hence maximizing profits. Further still, most of the site work and finishing works are subcontracted with the objective of creating job opportunities to the rural poor without qualification and proper on-the-job training and subsequently the effects are manifested by poor workmanship on the buildings. [2] and [3] recommend and suggest that as responsible professionals in the built environment, it is good for the construction companies to emphasize the need for use of qualified personnel in all construction activities as a step towards restoring sanity in the industry. According to [8], it is believed that unprofessional conducts contribution is not small measure to the menace of building collapse in Nigeria. Such unprofessional conduct like bribe collection from contractors, professional acting in the capacity beyond the scope of his profession, etc. has a negative effect indirectly on the building and may finally result into collapse of buildings.
communication system However, due to the complexity in construction industry several concurrent communication problems occur because no proper channeling is adopted to manage and control the communication process [17]. A study by [12] found out that that effective communication in construction is seriously hampered due to a lack of appropriate data channels, improper channel and inaccurate data transfers. [18] stated that, unclear channels of communications result in project delay. It is therefore very important to standardize the channels of communication in construction industry to fasten and ease the communication process. Dispute is a common issue that occurs in construction industry. It causes an impact on the main project components such as cost, time and quality of construction projects [19]. Dispute is commonly known as an endemic and chronic character of construction industry [20]. It was emphasized by many researchers; poor communication among construction industry is one of the main causative factors of dispute occurrence. It is, therefore, a major consequence of unsuccessful communication. [21] identified poor communication among construction parties as one of the significant causes of dispute. Lack of communication skills is considered of the utmost important diffusing factor to cause dispute in construction industry. Therefore, effective communication is very important to improve the relationshipbetween the project team [22].

Natural Disasters Such as Earth Quakes, Floods, Fire
One of the major natural factors that result into building collapse is rainfall and others may include temperature and pressure [7] and [2]. [25] Identified causes of building failure as due to natural occurrences such as earthquakes, tornadoes, floods, etc. Other causes include factors such as: omission, carelessness, leading to use of deficient structural drawings, absence of proper supervision of projects, alteration of approved drawings, use of substandard materials, corruption in the Nigerian system, building without approved drawings and translocation of building plans to different sites.

Lack of Maintenance Culture
The necessity for maintenance work on buildings is noted in the fact that all buildings, as well as the materials and components therein, deteriorate or suffer loss in aesthetic, strength and or functional value, with exposure to the elements of weather over time. The appearance and life span of a building and also the quality of the materials would be affected depending on the manner to which maintenance is adhered to, in the building [26]. If the design process is to be enhanced, the building team needs to come together and contribute towards the building's maintainability at the project inception rather than leaving it for the maintenance personnel at the end of construction to battle with the curative measure [27]. It is often said that building defects start on the drawing board, but in some cases, they can originate at an earlier stage [23]. Inadequate brief may lay down totally unrealistic cost limits or fail to give vital information on the building. Design deficiencies could result in a building disaster if adequate attention is not to the design of bearing support, calculation errors, deformation, shrinkage problems, errors in assumed loading (especially wind), and changes in alteration of existing structures -all these could contribute substantially to building failures and disasters. [26] further stated that a skillful design can reduce the amount of maintenance work and also make it easier to perform, since good maintenance begins on the drawing board.

Impact of Building Failure in the Construction Industry
The consequences are usually in the form of economic and social implications [28]. These include loss of human lives, injuries, economic waste in terms of loss of properties, investments, jobs, incomes, loss of trust, dignity and exasperation of crises among the stakeholders and environmental disaster. Apart from loss of lives (mostly innocent citizens), many other people has been rendered permanent disable in one form or the other as a result of increasing rate of building collapse in the country [3] and [7].

Methodology
The design employed in this study was descriptive survey method. Descriptive design is a method of collecting data by interviewing or administering a questionnaire to sample of individuals. This method is preferred because it allows for careful comparison of the research findings. It was the descriptive survey that helped to determine the causes of building failure in the construction industry. This required primary data collection on quantitative data for comparison. The study was designed to get opinions from clients, consultants and contractors of construction companies in regards to the causes, effects, as well as mitigation measures of building failures in the construction industry. The possible causes of building failures were identified from literature and these factors were tested with the stakeholders of the construction industry in the study area to seek their opinion on these causes by way of ranking them based on relative importance index (RII). Also effects of building failures were identified from literature and questionnaire was developed and administered according to these factors to get the opinion from respondents.
A quantitative approach was used to understand the perception of respondents in Osun State capital towards Industrial Engineering Letters www.iiste.org ISSN 2224-6096 (Paper) ISSN 2225-0581 (online) Vol. 12, No.1, 2022 the factors causing building failures in the construction industry. The qualitative approach was employed to have more understanding of the phenomena. A sample size of 136 respondents was determined from the table developed by [30] where a known population of the selected respondents was 210. The respondents were drawn from a population of supervising engineers, site engineers, site foremen, clerk of works and clients from the Ilesha, Ife, Osogbo, Iwo and Ede. Purposive and stratified sampling was used to determine the respondents but also key informants were purposively identified. A sampling frame of stakeholders in the construction industry was selected from civil servants, politicians, contractors, consultants, beneficiaries/users, and civil society organizations. Direct interview was also adopted as a method for data collection partly due to its cost effectiveness and its strength of capturing empirical data in both informal and formal settings. The interview guide consisted of both open and closed ended questions. All the necessary procedure of interviewing and usage of questionnaire were adopted in order to satisfy the objective of the study.

Validity and Reliability
Before the detailed field survey, a pilot survey was conducted using a total of 10 respondents within the domain of the study. In this study, data reliability was achieved by pre-testing the questionnaire on a selected sample of three experts. Contents of the questionnaire were assesses to ascertain whether they included or represented all the content of the research in the study. A content validity index (CVI) was computed using equation (1) and was established to be 0.87 implying that 87% reliabilityof the questionnaire was used for data collection.
CVI=n/N (1) Where; n -number of items considered relevant N-Total no. items. A question is considered valid when CVI is above 0.6 as the least recommended CVI in survey studies (Amin, 2005). Reliability of data was tested and assessed using Chronbach's Alpha using SPSS software. The results are displayed in table 1.  Table 1 indicate that there is high internal consistency. This is because the Cronbach's Alpha is high and close to one. This shows that the data used were reliable.

Results
The data were analyzed according to the research objectives i.e. to establish the causes of building failures and its impact in the construction industry.

Consultant Related Causes
The respondents were requested to rate their opinions on the consultant related factors that affect building failure in the construction industry. The responses were measured on a five-point likert scale as: strongly disagree (1), disagree (2), not sure (3), agree (4) and strongly agree (5). This section presents the results as shown in Table 2. Poor communication/ Coordination of the consultant and other stakeholders 0.54 Based on the computed Relative Importance Index (RII), the findings of the study reveal that inadequate supervision of works (RII=0.79) was the leading cause of building failure. This is in agreement with [1] and [3] which revealed that, the quality of site supervision has a major influence on the overall performance and efficiency of construction projects. Respondents agreed to a high extent that inadequate experience of the consultant

Contractor Related Causes
The respondents were requested to rate their opinions on contractor related factors that influence building failures in the construction industry. The responses were measured on a five point Likert scale: Strongly disagree (1), disagree (2), not sure (3), Agree (4) and strongly agree (5). This section presents the outcomes of the analyses as depicted in Table 3.  Table 3 indicate shortage of equipment (RII=0.76) was the leading factor that causes building failure.This result is in agreement with the study by [31] where many contractors complained that they had inadequate plant and machinery and indeed often this is the case. Financial difficulties (RII=0.68) were ranked second. Improper construction methods and poor planning and scheduling of contract activities both ranked number three with RII=0.65.
Inaccurate cost estimates and poor site management and supervision of contract activities ranked 4 th and 5 th respectively. Inexperienced staff (RII=0.56) ranked number six as a cause of building failure.

Client Related Causes
The respondents were requested to give their opinions on client related causes of building failure in the construction industry. The responses were measured by a five point Likert scale; strongly disagree, disagree, Not sure, Agree and strongly agree. According to the study findings, clients' cash flow problem was identified as the leading cause of building failure with RII=0.67. The main factor contributed by clients is when they take longer than the stipulated time in terms of the contract to certify the claim. This was followed by unavailability of incentives with RII=0.66. Slow decision making and variation of orders ranked number three with RII=0.62. Poor communication/coordination of the client and other parties ranked number nine with RII=0.52. Unrealistic contract duration ranked number 10 with RII=0.5

External Related Causes
The respondents were asked to give their opinions on external related causes of building failure in the construction industry. The responses were measured on a five point Likert scale; strongly disagree (1), disagree (2), Not sure (3), Agree (4) and strongly agree (5). The results are resented in Figure 4. Inflation in prices ranked 1st with RII=0.70. [7] and [2] observed that the rate of inflation can cause serious problems in the economic accruals or rate of return to contractors for works undertaken, thus loss of profit. Deferring site conditions ranked second as the cause of building failure with RII=0.66. Shortage of construction materials in the market was ranked number 3 with RII=0.64. If the materials needed to carry out the project are in short supply, it will cause the project to be delayed consequently leading to failure. Acts of God was ranked number 10 with RII =0.48.  Table 4, consultant related causes had the highest contribution on building failure with a mean RII score 0.62. This was followed by contractor, external and client related causes respectively. This is attributed to the fact that consultants provide the technical advice and monitoring services to executors of these

Impact of Building Failure
The respondents were requested to give their opinions on the impact of building failure in the construction industry. The responses were measured on a four point Likert scale; Very High (4), High (3), Low (2), Very low (1). The results are presented in Figure 5 which indicate that cracking foundation was ranked as having the leading impact of building failure with RII=0.70. Cracks may be a sign that the foundation was laid on a poorly compacted base or poorly graded soil; wide cracks could signal a foundation problem. Water leakages through the roof was ranked number two with RII=0.68. According to [33], water proofing is known as the main contributor to the failure of buildings that leads to the moisture problems. Cracks that affect the structure of the building were ranked third with RII=0.67.

Discussion and Findings
The findings are summarized in line with the objectives of the study which were to establish the causes of building failure and to evaluate their impact on building failure in the construction industry in Osun State.

Consultant Related Causes
The study found out that inadequate supervision of works was the leading cause of building failure with RII=0.77. This is in agreement with [1] and [4], the quality of site supervision has a major influence on the overall performance and efficiency of construction projects. Inadequate supervision is believed to be one of the major causes of rework. Respondents agreed that inadequate experience of the consultant is the second cause of building failure with RII=0.69. According to [2] and [30], lack of experiences and competency of laborers must be taken into account as a factor that contributes to poor workmanship as "productivity cannot be achieved by speed and harder work only without adopting better work practices. Conflicts between consultant and design engineer with RII=0.68, was ranked number three.

Contractor Related Causes
Respondents agreed shortage of equipment and materials leads to building failure with RII=0.76. This is in agreement with the study by [30] and [4] where many contractors complained that they have inadequate plant and machinery and indeed often this is the case. In many instances, however, it is not so much the absence of plant which is the problem but shortage of spares, which often have to be imported, and lack of good mechanics and capable plant operators. Financial difficulties were ranked second with RII=0.69. Money or rather lack of it is probably the most discussed problem of contractors in developing countries. Contractors need relatively few fixed assets and have a low capital base compared with other industries. They should need relatively little working capital because the traditional contractual arrangements provide for payment as the project proceeds.  Improper construction methods and Poor planning and scheduling of contract activities both ranked number three with RII=0.66. This is in conformity with [7] and [3]. Substandard material especially reinforcement rods, steel sections and cement can contribute immensely to failure of buildings. Inaccurate cost estimates and Poor site management and supervision of contract activities ranked 4 th and 5 th respectively. Inexperienced staff ranked number six as a cause of building failure with RII=0.56.

Client Related Causes
Most respondents agreed that clients cash flow problems is major cause with RII=0.67. This was followed by unavailability of incentives with RII=0.66., Slow decision making and variation can cause serious problems in the economic accruals or rate of return to constructors for works undertaken, thus loss of profit. In the traditional orders ranked number three with RII=0.62.

External Related Causes
Inflation in prices ranked 1st with RII=0.70. Inflation causes serious problem to contractors. Inflationary forces render submitted bids unrealistic. This has made contractors' quantity surveyors more aware of the need to price inflationary risk at the pre-contract stage [2] and [8].

Mitigation Measures
In summary, within the Ugandan construction industry, factors relating to defects can potentially be avoided if qualified professionals are appointed to exercise due diligence and if professional teams are given the opportunity to guide contractors during the contract. The cost of appointing reputable professionals in their advisory capacity has to be weighed against the cost of both social and economic constraints. The appointment of qualified construction-industry professionals to implement and maintain quality-management systems will alleviate the current problems in respect to quality of buildings within the country. The serious shortage of competent people at both local and national government level to evaluate and administer construction projects and identify contractual irregularities on all sides ultimately contributes to defective construction.
The study further recommends that organizations should consider adopting modern information and communication technologies in carrying out monitoring and evaluation activities. Skill levels should be enhanced to meet the needs of monitoring and evaluation systems. With regard to the causes of defects, it is recommended that professionals, especially contractors, concentrate on improving or implementing an effective qualitymanagement system. Defects must be viewed as a risk; due to the likely financial implications. The professional teams must ensure that they become more knowledgeable with regard to the effects of defects. Defects do increase the project restrictions of time and cost and affect other elements such as quality.

Conclusions
Based on the study findings, it was concluded that there is a great influence of consultant related causes of building failure. The study further concluded that the quality of site supervision has a major influence on the rate of building failures and hence performance and efficiency of construction projects. The literature indicated that cracking is a frequently occurring manifestation of defects. This is confirmed, to a degree, by the empirical results from this study. Water leakages through the roof were rated as the second most frequently occurring type of defect in houses.