Bill of Quantities (BoQs)
This refers to a specific methodology for scheduling construction costs in the UK though in practice most countries use similar procedures for presenting costs. For a construction the common factor is that they all derive a final cost of construction as a lump sum or as a cost per unit of area (m²/ft²) etc. it is only as question of presentation and the understanding of the inclusions and exclusions to those lists that are different. A basic Bill of Quantities could be a simple a six lines of presentation, for example foundations, building frame, walls and windows, roof, services and extras but that of course is imprecise and not a satisfactory basis for tendering or budgetary control for such constructions. It is the need for greater definition that has expanded these listings and need for a higher level of precision has developed them into set schedules and commonly agreed formats for a common understanding. For larger, more complex construction there may be many thousands of lines of cost presented as long as they are portrayed in the agreed and clearly understood format. Though I have referred here to the UK system for the ease of presentation the common requirements are replicated in other countries with often minor variations, for example the NEN system in the Netherlands and the DIN system in Germany and Austria. Typically the schedule follows the logical sequence of the construction so site preparation, foundations, building frame follows through the listings to final completion. It is often the treatment of the non-constructive cost elements that creates the greatest disparities between national systems. These can include/exclude professional fees, insurance, planning costs, nation tax charges, contingencies, contractors mobilization, inflation, constructors profit and many other factors. The most important component of each national system, mostly dictated by tradition is that there is a clearly understood and commonly agreed basis for the Bill of Quantities. The typical procedure for a construction is that the project will be designed by an architect who than hands it over to a cost engineer. The schedule of components are then taken off from the drawings and specification provided in a set sequence to create a Bill of Quantities. The important part of that Bill of Quantities is that the items are defined satisfactorily to enable a cost of supply and fix can be derived, defined and costed. A Bill of Quantities maybe be provided by the clients as part of the tender documentation though in some countries no Bills of Quantities are provided leaving it to the contractor to derive the cost centres themselves. The fact that each contractor needs to carry out this work is an additional cost which can be saved if a measured bill is provided. The Bill of Quantities is then costed and provided to the client as an inclusive part of their tender offer. This becomes part of the contract and in subsequent transaction is the basis for approving the request for payment for satisfactory completion of those works and/or not! This allows for quantifying short falls, measuring additional works and generally providing an audit trail for all expenditure undertaken within the contract.