Quantity Surveyor Interview Questions & Answers (with Model Answers)

Model Answer

I start with a cost plan against the brief, benchmarking elemental rates so the budget is realistic before design firms up. Through design I track the developing cost against the plan and challenge anything drifting, then prepare tender documents and analyse returns to recommend an award. In construction I value the works monthly, manage variations through change control and forecast the final account continuously. At completion I agree the final account fairly and close out cleanly with full records.

Model Answer

I value variations using the contract's valuation rules, applying contract rates where the work is similar and fair rates where it is not. I keep clear records of instructions and resources so the valuation is defensible. I assess the time impact as well as cost, because a change can affect the programme. Being fair but firm protects the client while keeping the contractor's trust.

Model Answer

On a project running over budget I led a value engineering exercise with the design team, focusing on cost-significant elements rather than trimming everywhere. We changed a facade buildup to an equivalent system that performed the same for less, and rationalised the structural grid. The exercise brought the scheme back within budget without losing functional quality. I documented each option so the client could decide with full cost visibility.

Model Answer

I assess it dispassionately against the contract and the records rather than reacting to the headline figure. I separate the genuine entitlement from the opportunistic and ask for the substantiation the contract requires. I respond clearly, agreeing what is fair and rejecting what is unsupported with reasons. This protects the client's position while keeping the negotiation professional and resolvable.

Model Answer

I maintain a cost report that reconciles the budget, committed costs, variations and the forecast final cost, updated every period. I forecast out-turn rather than just reporting spend, so risks surface while there is time to act. I tie the report to the risk register and contingency drawdown for a complete commercial picture. Clients rely on these figures, so accuracy and honesty are everything.

A bill of quantities lists measured quantities of work for tenderers to price, giving a lump-sum tender comparison. A schedule of rates prices unit rates without firm quantities, used where the scope is uncertain and work is valued as it is carried out. The BoQ suits defined scopes; the schedule of rates suits variable or measured-term work.

A provisional sum is an allowance for work not yet fully defined, to be expended and adjusted as the work is detailed and instructed. A prime cost (PC) sum is an allowance for the supply of materials or goods by a nominated or selected supplier, with the contractor adding for fixing and profit. Both are placeholders adjusted against actual cost.

Retention is a percentage, often around three to five percent, withheld from each interim payment as security. Half is usually released at practical completion and the remainder at the end of the rectification or defects liability period once snags are cleared. It protects the client against non-completion and latent defects.

Liquidated damages are a pre-agreed, genuine estimate of the client's loss for late completion, recoverable without proving actual loss. A penalty is a punitive sum disproportionate to loss and is generally unenforceable. The figure must be a reasonable forecast of loss when the contract is signed to remain valid as liquidated damages.

I follow the applicable standard such as NRM or POMI, which defines measurement rules, units and what each item includes so pricing is consistent. Measuring to the standard means tenderers price like for like and disputes over what an item covers are minimised. It underpins accurate bills and fair valuations.

A scheme came back over budget at tender stage and the client was anxious. I led a structured cost-reduction review with the design team, targeting the elements with the biggest cost impact. We re-specified a few items and adjusted scope where value was low. The revised tender came in on budget and the client proceeded with confidence in the numbers.

A contractor's final account was well above my assessment, driven by disputed variations. I prepared a detailed line-by-line position backed by records and met them to negotiate. By conceding where they were genuinely entitled and holding firm where they were not, we settled close to my figure. Both sides accepted the outcome as fair and the account closed without dispute.

I spotted that a key material was rising sharply in price and the contractor had not yet ordered it. I flagged the exposure in the cost report and recommended early procurement to lock the rate. The client agreed and the order was placed before the next price rise. We avoided a five-figure cost increase by acting on the forecast early.

A client struggled to understand why the forecast final cost exceeded the original budget. I produced a simple bridge showing each movement from budget to forecast, attributing it to scope changes and risk. Seeing the drivers laid out plainly, the client understood and approved the additional funding. Clear communication turned anxiety into an informed decision.