The choice of a contract form and an appropriate procurement route are primary determined by the cost, time and quality.
The cost is a decisive factor in terms of building contracts as it involves budget constraints that often appear unrealistic or non-negotiable over the period of the programme. Making the QS’s role important, it also raises the need for clear and accurate cost assessment from the Architects along with comprehensive drawings, specification documents at tender stage. Additionally, the architect/lead consultant has a duty to advise on all long-term implications. Design and Build appears to benefit over delivery time and cost as single-stage tendering may result in longer timescales with higher control, opposed to cost and quality, where the programme benefits from the construction management. On the contrary, two-stage tendering may reduce the programme with potential rise in cost.
The time often conflicts with quality as it is saved by the overlapping of detail design and construction phases. As real-time planning arises through effective management, sufficient time must be allowed for all the issues to be properly considered at the pre-contract stage, whatever the procurement method. Also, predictability is essential to all clients due to a history of projects with overdue construction period. Lastly, where commercial or external pressures exist to complete on time, a guaranteed completion date is required with the contractor pricing for the risk, making it even harder when it comes to projects requiring restrictive operations during certain times of the working day (e.g. Domestic projects).
The quality of the resultant project is set and issued within the specification document where the measurable standards, by which the degree of quality will be achieved and assessed, are defined. Often set parameters influence the quality, where the building is called to perform against specific constraints such as durability, low maintenance, historical context which either affect the construction programme or even require higher degree of site quality control by both the contractor and any body responsible for imposing conditions. Hence quality is often related with higher time-frame and increased cost.