In 1970 an act was promulgated that had the effect that only quantity surveyors were allowed to draft bills of quantities (BOQ). The act empowered the minister of public works to reserve certain work for quantity surveyors, and in a ministerial note something to the effect that bills of quantities may only be produced by quantity surveyors was established. If read with other parts of the act, it was clear that it all meant that only a professional person, which in turn meant properly trained and experienced as a quantity surveyor, may produce bills of quantities.

In 2010 it sounds very protectionist, but from what we nowadays see regularly of half-baked schedules or lists of some items with some form of quantities and rates, makes one think carefully about whether it is perhaps sometimes necessary to protect society against itself.

The problem is that it appears so simple to produce a bill of quantities: besides, nearly anyone of reasonable arithmetical training and capable of reading a drawing can do a few sums and compile quantities of volume, area or length; or count the number of widgets required.

What is overlooked, is the fourth dimension, and the unseen foundations underpinning the fourth dimension.

The fourth dimension is the description: what it is that the quantity is associated with, how the unit makes sense to be able to translate the particular item to money by being able to calculate an unambiguous rate or price for it. Very often, the fourth dimension is not even directly in the description, but in part or even fully implied. The fourth dimension is abstract, albeit presenting itself at first glance at being concrete, being real.

The primary document to create the fourth dimension, is the preambles or method of measurement, that text that describes how the quantities are determined to form a mutually understood rules base of exactly how quantities are determined for the particular purpose, which items are expressed separately and which are implied or included by expanding the description of the particular item. E g: anyone that has been involved in a piping remeasure, would testify on the arguments around exactly what a closure is and how it is costed.

The fourth dimension

In some instances, the fourth dimension is definitive and easy to understand: the description of the item together with the unit of the quantity, is the fourth dimension for an item measured in volume: id est when talking [length x width x height] everybody understands the three dimensions. To actually be able to price it, to associate a cost rate to it, the fourth dimension being the [description + unit] is required, and as self-explanatory as it may sound, it is most often not fully accounted for when bills of quantities are drafted by non-quantity surveyors.

Consider the following example:

Concrete 10

Does this mean 10m³ of concrete? In the context of a bill of quantities for civil works, the answer may be: “Probably”. Some would say: “Of course” – until six months into the contract it does not suit one of the parties to interpret it that way.

Thus – and this is still the easy part – the item should rather read (in bill of quantities format):

Concrete m³ 10

The fourth dimension – the description – in this example is however insufficient. By adding a variety of fourth dimension options, it becomes clear that the unit price for the item can not yet be concluded, even though the three dimensions of volume calculations are already concluded in the 10, and demarcated by the m³:

[Mass] concrete m³ 10

[15MPa] concrete m³ 10

[30MPa] concrete m³ 10

Mass concrete of (say – once again something is lacking – 10MPa) is significantly cheaper by e g cement requirement considerations per m³, than 30MPa concrete. Note that by virtue of habit of reading, the 30MPa tends to ring the “reinforced concrete” bell, yet it is not clear in the above whether this is indeed what is required. Since mass concrete is easier to cast than reinforced concrete, there is a marked difference in rate per unit for mass concrete and reinforced concrete. (Concrete strengths exceeding 10MPa is not common for mass concrete, but we have come across interesting exceptions in abutment walls for major crusher installations at large-scale mines).

Another interesting example is found in electrical installations, where often the cable type and size is mentioned in reasurable detail (e g “25mm2 x 4 x core PVC/SWA/PVC 600/1000V cable”) which is quite priceable on a per metre installed basis, most often supported by a very detailed technical specification elsewhere in the document, but if the contract was won with a very keen tender, the fun starts once the cable installation commences on site:

  • the engineer is convinced that stainless steel individual strapping is the norm, but the contractor is adamant that he allowed for the much cheaper PVC strapping across multiple cables
  • the contractor wants to be paid for metres of actual cable installed, with an allowance for “snaking” and coiling on the ends to provide for the uncertainties in final positioning of the equipment to be hooked up, whilst payment should be based on the net installed route length (straight, flat line) and minimum necessary allowances at the ends
  • we have come across cases where the engineer insisted that terminations of the cables ends are deemed included in the average per metre rates, whilst the contractor is likely to insist that such is separately counted and priced by number.

A bit of pre-emptive writing in a preamble to the bill of quantities such as the following does wonders to prevent subjective arguments and makes the priced bill of quantities the objective price determination instrument it intends to be:

2. Cables

2.1 Cables lengths shall be measured in metre as the net route on the centre line of racking and other cable support from gland entry to gland entry, with allowances for joining into equipment added as follows:

• 0,5m for entering motors or other equipment

• 1,0m for entering junction boxes, fields isolators, stop/start stations and the like

• 2,0m for motor control centers, transformers, PLC cubicles, power cubicles and the like

Descriptions for cables shall include the fixing method and numbering requirements.

Separate items shall be measured for different cable specifications according to core thickness, number of cores, armouring, insulation, screening and any characteristics influencing the cable cost.

Rates for cables shall allow for snaking, threading, slacking and waste.

2.2 Cable terminations shall be measured in number. Rates shall include for neat cutting and making off cable, careful preservation of inner insulation as required, lugs, pins, shrouds, attaching to terminals, numbering and loop testing.

(abstract from VDDB Preambles to Bills of Quantities for Electrical and Instrumentation Installation, Version 2.1)

There is more to the compilation of a robust bill of quantities that does not become a burden on the contract and does not fulfil its intended role to provide a manageable objective cost calculation pre-agreed platform. The old legislation and its regulations did not expressly indicate that it applied only to the building industry, but at the time quantity surveying was clearly tied to the building industry and it went (almost) without saying that engineers did there own bills of quantities for their type of works. The emergence of the SABS 1200 (now SANS) with its clause 8 methods of measurement for use by civil engineers, supported this view that engineering works were allowed to do bills of quantities without quantity surveyors.

Quantity surveyors have since become involved in engineering works, or to add a proper fourth dimension exactitude to this statement: some did. Those who do this well, add value to engineering works, but unfortunately some engineers may be excused for their disapproving attitudes towards quantity surveyors on their projects based on experience of quantity surveying services delivered by those who deserve the title of brick counters, and should rather stick to it. This is due to the fact that quantity surveyors are trained for the building industry and that’s that. The puny efforts of the universities to add some engineering works knowledge into the training, is not worth mentioning. This critisicm is perhaps overly harsh, since the relative simplicity of the building industry is the best training ground for quantity surveying principles, and has enough content to be a full course training. This view however does not solve the problem of how to provide a more consistent and properly informed and skilled quantity surveying service to the engineering industry.

Notwithstanding, engineers are encouraged to look for those few quantity surveyors which by whatever means have obtained the necessary domain knowledge and use their bill of quantities principles well to serve the engineering industry. There are some of us that truly understand the engineering industry content, and can provide BOQ’s that really means “bills of quantities” and not burdens.

Leonard van der Dussen

About Us

VDDB provides project structuring, execution and control services that makes projects predictable and controllable. Some clients prefer the full project office function, including procedures, procurement, contract administration, policies and general project execution and co-ordination, and use selected services.


The concept of analytical quantity surveying is one of numerous enhanced services where traditional skills are merged with information management tooling to provide strongly enhanced project services in a fast world which is keen for optimisation.

Get in Touch

  • Phone:
    +27 12 534 3160
  • Mail:
  • Address:
    Fountain Square, Floor 2, Office 204,
    78 Kalkoen Street, Monument Park X2, Pretoria, South Africa, 0157