The Quantity Surveyor (‘QS’) is a construction professional who often works alongside the Project Manager with the main responsibility being the measurement of buildings and cost. The role is often not well known to the newcomers to the construction process.

The ‘QS’ role commences early on at project conception and often continues right the way through to physical completion of the build and beyond to the final agreement of all costs and respective payments depending on the amount of assistance the Owner-Builder requires.

With the Owner-Builder’s first sketch drawings, the QS will provide a cost estimate for the proposed design taking into account such factors as the building type, site location, floor area and the level of finish. Typically this first estimate will be presented as a range from lowest to highest anticipated cost providing valuable guidance at an early stage of the new home project.

QS Perth offer all Owner-Builders a free initial estimate of their building cost

Once the Owner-Builders new house design has progressed through to the more detailed ‘working drawing’ stage, the QS is then able to undertake a detailed measurement process producing a ‘Bill of Quantities’ (BoQ).  When populated with priced rates by the QS, the BoQ provides a detailed and significantly more accurate estimate of the total cost. This accuracy enables design and cost decisions to be made well before construction commences.

The BoQ document also provides the Owner-Builder with a valuable tendering document on which subcontractors competing for the work will insert their priced rates and return for the Owner-Builder to review. This has numerous benefits for the Owner-Builder over and above the often ill-fated method of only sending the drawings and specifications out to the tendering subcontractors for which a lump sum price, with little or no detail, is often returned.













The value clients get from a QS Perth produced Bill of Quantities include:

  • Effective Tendering: A BoQ generally increases the number of priced tenders returned back to the Owner Builder as the measurement process has already been provided. Subbies don’t like measuring quantities and nor should they, it’s the job of the QS!
  • Tendering Uniformity: The BoQ document provides a ‘level playing field’ for competing subcontractors to tender on as they are all issued with the same document for pricing.
  • Pricing Variations: The subcontractor’s priced rates are clearly identified avoiding potential disputes. If quantities need to change during construction, for example more concrete in the trench foundations required due to a soft spot in the ground.
  • Payment Accuracy: Subcontractor payments can be accurately calculated for the value of work done.
  • Cashflow Monitoring: An essential tool for measuring subcontractor and supplier quotations against budget so you don’t run out of money towards the end of the project.
  • Finance Approval: An independent and professionally prepared document which, in conjunction with key quotations, can help satisfy the increasing demands of banks and financiers for lending.
  • Bank Progress Payments: The priced BoQ document will enable an accurate Cash Flow statement to be quickly produced when aligned with the building programme. An accurate Cash Flow will enable the Owner-Builder to plan the finance payments to identify outgoing monies and timing.
  • Buildability Advice: During the BoQ measurement process, an experienced Quantity Surveyor will thoroughly examine the drawings and specification well in advance of project commencement. Queries raised are attended to before these manifest as frustrating, costly and time consuming construction phase problems.


QS Perth uses specialist CostX® software to rapidly and accurately produce BoQ documents. The use of such software enables QS Perth to offer big Quantity Surveying firm results for small QS firm fees!


Owner-Builders   |   Architects   |   Builders