QS Guide · Chapter 01

Introduction to Quantity Surveying

Understand what quantity surveying is, who AIQS is, what a Certified Quantity Surveyor does, and how QS relates to cost estimating and the international RICS framework.

QS Guide Chapter 01 of 5

00Overview 01Introduction 02Methods of Measurement 03Cost Planning 04Contract Administration 05Final Account

What & Who

What is Quantity Surveying?

Quantity Surveying (QS) is the professional discipline of measuring, valuing and managing the financial aspects of construction. The QS practitioner translates design drawings and specifications into a structured, auditable measure of work — the Bill of Quantities (BOQ) — and then administers the commercial life of the contract from tender award through to final account.

The discipline sits at the intersection of engineering, contract law, and commercial management. It requires the ability to read drawings and specifications correctly, the discipline to measure to formal published standards, and the commercial judgement to interpret rates, allocate risk, and resolve disputes.

The AIQS — Australia's QS Body

The Australian Institute of Quantity Surveyors (AIQS) is the peak body for QS in Australia. AIQS sets the Standards of Practice, accredits Certified Quantity Surveyors (CQS), publishes the Australian Standard Method of Measurement (ASMM) and the Best Practice Costing Manual, and operates the Continuing Professional Development framework that members must complete to retain their credential.

AIQS membership grades range from Affiliate through Associate (AAIQS), Member (MAIQS), and Fellow (FAIQS). The CQS post-nominal is the gold-standard accreditation that signals competency to the market.

How QS differs from cost estimating

Cost estimating develops the predicted cost of a future scope of work, typically built up from first principles or using parametric methods. It is forward-looking and assumption-driven.

Quantity surveying is the formal measurement and valuation discipline that turns design information into a structured, auditable BOQ used for tender, payment, and variation assessment under a contract. It is rule-driven (ASMM) and audit-grade.

The two disciplines are complementary: cost estimating sizes the project; QS administers it commercially through delivery. Senior practitioners often do both.

RICS — the international peer body

Internationally, the Royal Institution of Chartered Surveyors (RICS) is the equivalent peer body. RICS publishes the New Rules of Measurement (NRM) series — NRM 1 (cost planning), NRM 2 (detail measurement), and NRM 3 (whole-life costing). Many Australian QS practitioners hold dual AIQS / RICS credentials.

Common Questions

Frequently Asked Questions

A Certified Quantity Surveyor (CQS) holds the AIQS-accredited credential and is qualified to prepare formal cost plans, Bills of Quantities, progress valuations, variation assessments, and final accounts. CQS practitioners follow the AIQS Code of Professional Conduct, complete annual Continuing Professional Development, and carry professional indemnity insurance to the AIQS standard.

No. Cost estimating develops a forward-looking prediction of project cost — typically built from first principles. Quantity surveying is the formal post-design measurement and valuation discipline used to prepare a Bill of Quantities, administer progress payments, and assess variations under a contract. The two are complementary; senior practitioners often do both.

For Australian-funded infrastructure, AIQS is the relevant body. For internationally-funded projects (resources, major PPP, foreign investment), the RICS New Rules of Measurement (NRM) framework is often specified. Many senior Australian QS practitioners hold both AIQS and RICS credentials and can work to either standard.

Need Expert Help on Your Project?

Cenex's RPEQ-certified team applies these standards in real Queensland infrastructure delivery every day.