An Assessment of Timber as a Sustainable Building Material in Nigeria (Review Completed - Accepted)
Timber, as a building material, was assessed for its sustainability using data from secondary sources. It established that a sustainable building material must be environmental friendly, affordable, flexible in usage and durable. Timber possesses these characteristics. The paper thus compared fuel energy required to produce timber as well as carbon dioxide released and stored during production with other common building materials such as steel, concrete and aluminium. It observed that 750 MJ/m3, 26600MJ/m3, 4800MJ/m3 and 1100000 MJ/m3 of fossil fuel energy is required to produce Rough Sawn Timber, Steel, Concrete and Aluminium respectively. The work revealed that timber stores as much as 250 Kg/m3 of carbon dioxide (CO2) and releases only 15Kg/m3 into the atmosphere. In contrast, Steel, Concrete and Aluminium store no carbon dioxide while they release 5320 Kg/m3, 120Kg/m3 and 22000 Kg/m3 respectivelyinto the atmosphere. Additionally plants, the primary source of timber, absorb carbon dioxide and release oxygen into the atmosphere during photosynthesis with a comparatively low thermal conductivity advantage. The paper consequently concluded that since timber is readily available in the country, it is a highly sustainable building material in the nation. It posited that the problems associated with the usage of wood, such as attack by insects, fungi, fire, depletion of natural resources etc can be ameliorated with the aid of preservative treatments, fire retardant and afforestation.
Keywords: Assessment, Building Material, Embodied Energy, Nigeria, Sustainable, Timber
PARTICIPATION OF INDIGENOUS CONTRACTORS IN NIGERIAN PUBLIC SECTOR CONSTRUCTION PROJECTS AND THEIR CHALLENGES IN MANAGING WORKING CAPITAL (Published)
Over the years, indigenous contractors in Nigeria have recorded a low level of participation and have often been sidelined in large scale construction activities. This has been attributed to, amongst a number of factors, mismanagement of funds and working capital which makes them prone to bankruptcy, with poor project execution and abandonment the likely outcome. The paper thus focused on studying the extent of participation of indigenous contractors in Nigerian construction projects, identifying and examining the most severe factors that hinder effective and efficient working capital management and affect the level or amount of working capital requirement of indigenous contractors. Literature studies, field survey and oral interviews were carried out to determine the major challenges faced by contractors in managing working capital and the extent of indigenous participation in public projects respectively, while a questionnaires were distributed to a selected sample of contractors in Imo state to obtain the severity weight of each factor. Findings revealed that evidently, the common challenges facing Nigerian indigenous contractors in Nigeria in the area of working capital management are low awareness of the need for working capital management, one-man business setbacks, under-capitalization, poor funding and cash flow problems, high cost of construction finance, economic recession, reckless spending and diversion of funds, poor project planning and control. Factors affecting the level of working capital requirements comprises: inflation, delays in interim payments, taxation at source and deduction of retention funds. Indigenous contractors also recorded a low level of participation on major public contracts. Results of the severity ranking exercise indicated that the problems of the one-man business set up is the most severe of the factors hindering proper working capital management, while deduction of retention fund and inflation respectively, ranked highest in factors affecting the level or amount of the contractors’ working capital requirement. It was thus recommended that in order to enable indigenous contractors realize construction projects within pre-planned cost, time and quality, reduce the incidences of project abandonment and improve their overall participation, there is need for concerted efforts on the part of the contractors to take appropriate steps in maximizing their awareness on the gains of proper working management and minimize incidences that will lead to cost escalation of his working capital requirement and on the part of the Government, a focused, political will to devise policies and create the enabling environment for improving indigenous content in the construction industry
Keywords: Challenges, Indigenous Contractors, Management, Nigeria, Participation, Working capital.