What quantity surveyors do and what interviewers assess
Quantity surveyors (QS) manage the commercial and financial aspects of construction projects: cost planning, procurement, contract administration, interim valuations, variation management, and final account settlement. Client-side QSs (also called Employer's Agents or Cost Consultants) represent the client's commercial interests. Contractor-side QSs manage the contractor's commercial position on a project. Interviewers assess: numeracy and commercial accuracy, contract knowledge (JCT, NEC, or other relevant forms), attention to detail, and the ability to manage commercial risk on behalf of the client or contractor.
Technical questions
"What is the difference between a Bill of Quantities and an Elemental Cost Plan?" A Bill of Quantities (BoQ) is a detailed, measured schedule of all the work items in a construction project, prepared using a standard method of measurement (typically RICS NRM2 in the UK). It is prepared at tender stage and used to price individual trade items. An Elemental Cost Plan is a high-level cost estimate prepared at early design stages, structured by element (substructure, frame, roof, external walls, etc.) rather than by measured trade items. Cost plans are updated as design progresses from order-of-magnitude at RIBA Stage 1 to a detailed pre-tender estimate at RIBA Stage 3/4.
"How do you value a variation on a JCT contract?" Under JCT Standard Building Contract, variations are valued using rates in the contract bills where applicable, pro-rated from bill rates where work is similar but not identical, or by a fair and reasonable rate where there is no analogous bill item. If rates are not appropriate due to the nature or timing of the variation, a daywork valuation may be appropriate, subject to prior agreement. Always confirm the variation instruction in writing before the work begins and agree the basis of valuation in advance wherever possible.
Behavioral questions
"Tell me about a time you identified a commercial risk on a project and how you managed it." Strong answer: the specific risk (under-measurement in the tender? a contractor submitting inflated variation claims? a design change creating significant cost uplift?), how you identified it, how you quantified it, how you reported it (in a Cost Report with a clear commentary, not buried in a schedule), and what action you recommended or took. Show you are proactive about commercial risk rather than reactive. "Describe a difficult conversation you had with a contractor about a commercial claim." Show negotiation skills, knowledge of contract entitlement, and the ability to disagree professionally without damaging the working relationship.
RICS chartership questions
For candidates working towards RICS APC (Assessment of Professional Competence): interviewers will often ask about your APC progress, your supervisor, and which competencies you are developing. Know the mandatory competencies (Client Care, Communication and Negotiation, Health and Safety, Business Planning, Accounting Principles and Procedures) and the core quantity surveying competencies (Cost Management, Contract Practice, Procurement and Tendering) well enough to give examples for each. RICS members interviewing for senior roles may be asked about CPD and their engagement with the profession.