Architecture / June 25, 2018 / .
Local contractors are usually at an advantage when competing for work. Contractors who have the capacity to construct work from within their own organisation should, in theory at least, be more competitive than those who sub-contract large proportions of the work. Current site management practice however tends to favour the widespread use of subcontractors. Nevertheless, the ability to attract labour and to source materials in the locality is an important factor in ensuring that unnecessary travelling and transport costs are not incurred in carrying out the work. Seeley notes that contractors will have to consider whether management, labour and plant resource requirements can be met from within the contractors own organisation or whether it will be necessary to recruit specifically for the project. The contractor will also have to consider what demands the proposed project would put on own plant, scaffolding and equipment.
The choice of the material, and hence the cost, may be influenced by factors other than aesthetic qualities. For example fast-track construction projects may use a steel frame in preference to an in-situ or precast concrete frame in order to reduce overall programme durations. Although the concrete option may be cheaper, the shorter programme achieved by using steel may offset this initial cost advantage. Technical decisions such as these are made for each building element and these have a direct bearing on the eventual cost. Where considerable repetition can be achieved it may prove economical to prefabricate certain structural elements or to standardise various components and fittings.
The factors influencing this decision include: Is the more expensive option a worthwhile investment? If it can be demonstrated that savings will arise as a consequence of incorporating the more expensive alternative, then the client is well advised to choose this option. The quicker the payback period, the more likely it is that the more expensive option will be chosen. How flexible is the client‟s budget to finance more robust, better quality or more economic structures or systems? Regardless of whether the client wants the more expensive alternative he or she may not be able to afford it. Retrofitting, however, is inconvenient, disruptive and much more expensive subsequently. Will the client occupy the building? Clients who develop to sell or lease may be less concerned with the operating and maintenance costs of the facility which will be passed onto the eventual purchaser or user of the facility. Clients who spend more initially will seek to recover their investment through higher rents or sales price. This approach may be adopted by future oriented private sector clients concerned with sustainability and green building issues. What is the life-span of the building? The shorter the planned life span of the building the less appropriate it is to incorporate robust and durable materials and systems.
Clients who prioritise cost over speed or who require fixed price lump sums will generally experience longer development programmes, as designs must be substantially completed before tenders can be obtained. This process may take a considerable amount of time as careful thought is required to develop and refine the scheme design. The design, in turn, influences the contractors construction methods which determine length of time taken to complete the contract on site.