1.2 The measurement process
Figure 1.1 provides a comprehensive visual representation of the measurement process typically followed in the preparation of a Bill of Quantities (BQ) for construction projects. The flow chart in Figure 1.1 underscores the sequential and integrated nature of the measurement process. It illustrates how various information sources (drawings, standards, specifications) converge through the act of measurement, either manually or digitally, to produce outputs (BQs) essential to the financial and contractual management of construction projects. This structured process plays a critical role in construction estimation, cost planning, tendering, and contract administration, and it integrates key inputs, tools, and outputs used by quantity surveyors and cost estimators. Understanding this process is crucial to develop the technical and digital competencies expected in the contemporary construction industry.
The process begins with the analysis of drawings, which are usually produced by architects, engineers and other construction professionals. These drawings include floor plans, elevations, sections, and details that define the scope and physical dimensions of construction works. Accurate interpretation of drawings is fundamental skill, as all subsequent measurement activities are based on the information available on the drawings.
As shown in Figure 1.1, the measurement process is guided by the standard methods of measurement, such as the ANZSMM. The standard provides a framework for how construction work should be described and measured. It ensures consistency in the interpretation of quantities across projects and between stakeholders.
Another key input in the measurement process is the project specification, which details the technical and qualitative requirements of materials, construction techniques, workmanship standards, and compliance obligations. Specifications often contain information not visible on drawings, such as strength grades of concrete and reinforcement types. Therefore, specifications complement the drawings and provide useful information for writing the descriptions of works.
After gathering and analysing these inputs, the measurement task can proceed. The measurement can be performed using one of two main approaches:
- On-screen (computer-based) measurement: This involves the use of digital tools such as RIB CostX software, which allows users to upload digital plans [Portable Document Format (PDF), Computer-Aided Design (CAD) files or images], calibrate them to scale, and perform measurements on screen with tools for length, area, and volumetric take off. This method increases efficiency, accuracy, and traceability in measurement. It also enables the integration of measurement data with estimating tools and BIM models, aligning with modern digital construction practices. This method is adopted in this handbook, and the details are explained in the subsequent chapters.
- Manual or Excel-based measurement: This method comprises transferring measured dimensions from drawings to take-off paper or Quantity Surveying (QS) paper. This method, while more traditional, remains relevant for building foundational skills in measurement logic, and can still be used in practice where digital tools are not available or suitable.
Both methods produce quantities for different trades of work. These quantities are typically recorded using standard item codes and structured descriptions based on standard rules. The final outcome of the process is the preparation of an Unpriced BQ, which presents a detailed list of works, quantities, and descriptions, ready to be priced by bidders.
