Architecture / May 1, 2018 / .
The issue of the cost of construction work is one that is rarely far from the minds of construction clients, design teams, constructors and, of course, quantity surveyors. The cost of constructing a building project is a primary concern for the vast majority of construction clients. Indeed one of the most common initial questions a client has is. What is it going to cost me? often followed closely by. can we do it any cheaper? Providing answers to such questions is a key objective of quantity surveyors, whose task it is to predict the likely cost of building work and to manage the evolving project design to ensure that the clients approved budget is not exceeded. This is a challenging task, which frequently involves one-off, unique, purpose made buildings, and the QS typically operates within a design team brought together specifically for that particular project.
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 geometry of a building has a major impact on costs. Building morphology is concerned with the size, shape and complexity of the building. This section provides a very brief outline of the principle morphological factors which influence the cost of building work. The reader is referred to the numerous publications which examine this topic in greater detail. The main design factors which impact on cost are: plan shape, size of building, wall to floor ratio degree of circulation space, storey heights total height of the building grouping of buildings.
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.