Architecture / June 12, 2018 /
The payment arrangements adopted on a contract directly affects the level of risk borne by the contractor. Where the contract is let on the basis of a drawings and specification lump sum the contractor assumes the risk for both the quantity and pricing. In lump sum contacts based on bills of quantities and remeasurement contracts the contractor assumes the risk for the pricing only. With reimbursement contracts the client assumes the risk for the quantity and pricing. The payment arrangement, therefore, directly motivates the contractors efforts to carry out the work in an efficient and economic manner. This in turn has a major impact on the final price paid by the client.
The site topography i.e. the natural site features, ground conditions and obstructions, existing and adjoining building, and underground and over-ground services all impact on how the building is designed and subsequently constructed. The nature of each site must be individually checked to establish potential problems. Greenfield developments cost less than brownfield sites which may incur significant demolition, site clearance and remediation costs. Heavily sloped sites require extensive stepping or cut and fill operations and such sites may be dangerous and adversely affect the working conditions and productivity of operatives and plant output. Sites with poor loadbearing capacity will require more expensive foundations while exposed or waterlogged sites will also reduce overall productivity. The cost of dealing with unforeseen ground conditions, archaeological finds and encountering uncharted buried services may be substantial and will be borne by either the client or contractor, depending on the form of contract employed.