During the construction phase of a project, a quantity surveyor (QS) acts as your financial watchdog and contract administrator. They track every dollar spent, assess contractor claims, manage variations, and make sure the project stays within budget from the first sod turned to the final sign-off. Whether you're building a new home, doing a major renovation, or overseeing a commercial development, having a QS on your team during construction can save you significant stress — and money.
Monitoring Costs Against the Budget
One of the QS's most important jobs during construction is cost monitoring. Before work begins, they will have prepared a detailed cost plan or estimate. As the build progresses, they track actual expenditure against that plan, flagging any budget overruns early so decisions can be made before costs spiral. This ongoing process is sometimes called cost control or cost management.
Regular cost reports — often monthly — give you a clear picture of where money has been spent, what is committed, and what is forecast to completion. This transparency is especially valuable on larger projects where dozens of subcontractors and suppliers may be involved.
Assessing Progress Claims
Contractors typically invoice for work completed at regular intervals — usually monthly — through what are called progress claims (or payment claims under the Construction Contracts Act 2002). Your QS will:
- Visit the site to verify the work claimed has actually been completed to the required standard
- Check the claim against the contract schedule of rates or lump-sum breakdown
- Recommend a payment schedule (the amount you should pay) to your project manager or directly to you
- Ensure retentions are correctly held where applicable
This process protects you from overpaying for incomplete or substandard work, and helps maintain a fair relationship with your contractor.
Managing Variations
Almost every construction project involves changes — a design tweak, an unforeseen ground condition, or a client-requested upgrade. These are called variations (or change orders). A QS will:
- Assess whether the variation is valid under the contract
- Value the additional or omitted work fairly, using agreed rates where possible
- Issue a formal variation order so both parties have a written record
- Update the cost plan to reflect the approved change
Without proper variation management, costs can creep up unexpectedly. A good QS keeps a running variation register so nothing slips through the cracks.
Contract Administration
Many QSs in New Zealand also take on a contract administration role, particularly on projects using standard NZS contracts. This involves:
- Interpreting contract conditions and advising on rights and obligations
- Issuing instructions and notices in accordance with the contract
- Assessing and certifying practical completion
- Managing the defects liability period and release of retentions
For projects requiring building consent, the QS works alongside the licensed building practitioner (LBP) and project manager to ensure financial and contractual matters align with the build programme. You can check LBP registration at Licensed Building Practitioners.
Procurement and Subcontractor Management
If subcontractors haven't been engaged before construction starts, the QS may assist with procurement — preparing tender documents, evaluating subcontractor quotes, and recommending awards. During construction, they may also check that subcontractor invoices to the head contractor are reasonable, which indirectly protects your overall budget.
Dispute Avoidance and Resolution
Construction disputes can be costly and time-consuming. A QS helps avoid them by keeping clear financial records, issuing timely payment schedules, and ensuring variations are documented properly. If a dispute does arise, the QS can provide expert evidence or assist with adjudication under the Construction Contracts Act. MBIE Building Performance provides useful guidance on building contracts and dispute processes in New Zealand.
Final Account and Project Close-Out
At the end of the project, the QS prepares the final account — a reconciliation of all costs, variations, and payments to arrive at the final contract sum. This document is essential for:
- Confirming the total amount owed to the contractor
- Releasing final retentions once defects are remedied
- Providing a cost record for insurance, depreciation, or future reference
For homeowners, the final account also gives you a clear record of what your build actually cost — useful if you ever need to update your home insurance sum insured. BRANZ offers research and guidance on building costs and quality that can be a helpful reference.
What Does a QS Cost During Construction?
Fees vary depending on project size and complexity. As a very rough guide, QS fees for construction-phase services on a residential project might be charged as a percentage of the construction cost, an hourly rate, or a fixed fee agreed upfront. It's worth getting a clear scope of services and fee proposal before engaging a QS so you know exactly what is included.
When to Call a Professional
If your project involves a formal building contract, multiple subcontractors, or a budget above a few hundred thousand dollars, engaging a qualified QS for the construction phase is strongly recommended. Look for members of the New Zealand Institute of Quantity Surveyors (NZIQS) or those holding a relevant qualification. Even on smaller residential projects, a QS can save you far more than their fee by catching overpayments and managing variations effectively. You can find qualified quantity surveyors in your area at tradedirectory.co.nz.
For any questions about building consents or what work requires consent under the NZ Building Code, always check with your local council or visit MBIE Building Performance.
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