HVAC contracting, the BOQ, and the Association of South African Quantity Surveyors’ standard system of measurement for building work.
The purpose of a Bill of Quantities (BOQ) is to set out the work to be done, or initially tendered on as indicated on the drawings and as contained in the specification in accordance with a predetermined set of rules.
The preparation of the BOQ, in the case of an HVAC project, is normally undertaken by the HVAC Consulting Engineer and the importance of a well-described and accurate BOQ cannot be understated. This document goes beyond being a tender summary but should be drafted in order to be utilised for project cost control during the execution phase of the project.
A well-described BOQ will provide the work detail split into sections, relating to different components of the overall project for example ducting, piping, equipment, etc, and will provide the tender adjudicator with the comfort that the work scope is understood by the tendering company. Essentially taking the ‘guesswork’ and risk out of the tendering process.
A BOQ should be set out in the following format:
- Item no
- Description
- Quantity
- Unit
- Rate
- Amount
Descriptions should be specific with relevant information, properly described and units must be in accordance with the standard system of measurement to assist the contractor in understanding the items and how they are measured.
The first standard of measurement for building work in South Africa was published in 1906 by the Transvaal Society of Quantity Surveyors, and thereafter standard systems were published on a national level with the seventh edition being released by the Association of South African Quantity Surveyors in October 2015.
The very first HVAC ‘Model Bill of Quantities’ with a standard system of measurement was drawn up in the early 1980s in a joint effort between Consulting Engineers and the South African Refrigeration and Airconditioning Contractors Association (SARACCA), and in subsequent years a number of revisions were made by sub-committees of SARACCA and Consulting Engineers. There has unfortunately been very little collaboration between SARACCA, Consulting Engineers and the Quantity Surveyors Association since these early interactions, however, today the standard system of measuring HVAC work is encapsulated in the Association of South African Quantity Surveyors “Standard System of Measuring Building Work” (seventh edition), under the mechanical work section and does set out rules for measurement.
It is evident that current practices by some consultants and quantity surveyors are to pay less attention to the descriptive requirements or the rules in the standard system of measurement, making it increasingly difficult for all parties to comprehend the “BOQ” produced for tender.
Many BOQ’s produced today are really no more than a price schedule of the work which still needs to be measured off drawings in order to accurately assess the quantities and work scope. This practice also reintroduces the guesswork and risk that a well-defined BOQ removes for the contractor.
The adjudicator of the tender would also have no idea of how to compare the rates include under each item, as inclusions and exclusions to these rates would likely differ vastly between all parties submitting tenders.
The person who is tasked with preparing the BOQ’s must prepare them in accordance with the rules set out under the standard system of measurement, otherwise, further confusion is introduced into the comprehension of the documents by the estimator.
In summary, a good BOQ will:
- Beset out in the correct format.
- Incorporate accurate and detailed descriptions of the work.
- Include the correct unit of measurement for bill items as set out in the standard system of measurement.
- Correctly identify ‘extra over’ rates and the main item over which the extra over rates are measured.
- Incorporate the entire work scope in measured quantities and not leave portions of the work to be measured as lump sums.
The lack of collaboration between SARACCA, Consulting Engineers, and Quantity Surveyors since the early 1980s, has meant that there are some areas of disagreement from contractors with the current standard system of measurement, and these are currently being addressed by a SARACCA subcommittee.
Some of the areas that are currently being addressed are:
- Spiral ducting (not relevant in the 80s) not to be measured as square meter units, but to be measured in meter length per diameter.
- Spiral duct fittings to be measured per fitting per diameter, and not as extra over to ducting.
- Piping to be measured per meter for each diameter and not to include jointing which should be measured separately.
- Pipe fittings to be measured separately per fitting per diameter for all sizes and not as extra over to pipe for each diameter.
- Items of equipment to only relate to the supply and installation of that particular item of equipment and all attaching piping, electrical works to be measured separately.
- Measurement of quantities of Control and Electrical works directly related to the HVAC installation.
The current fast pace of contracting and information flow accentuates the importance of a sound and accurate BOQ. Tendering lead times are far shorter than prior years, giving the estimator less and less time to provide an accurate set of tender documents for adjudication of the tender price and for cost control of the project work during the execution phase.
Projects are often not fully designed at the time of tender, and an accurate BOQ provides a means of cost control over the life of the project as changes to work scope are issued. The importance of a standard and accurate BOQ should not be underestimated by all contracting parties on any project.