Not every construction project needs a quantity surveyor. For smaller, straightforward works with a clearly defined scope and fixed contractor price, you may be comfortable managing the costs yourself.
However, a quantity surveyor becomes increasingly valuable as a project grows in cost, complexity or financial risk. If you are planning an extension, renovation, new build or development where several contractors are pricing the work, costs are uncertain, or payments will be made in stages, professional cost advice can provide much greater clarity.
A quantity surveyor can become involved before construction begins and remain involved through to completion, helping establish budgets, compare contractor prices, monitor payments and control additional costs.
This article will cover:
- What does a quantity surveyor actually do?
- When should you appoint a quantity surveyor?
- Who is a quantity surveyor useful for?
- Do you need a QS for an extension, renovation or new build?
- How does a QS help control construction costs?
- What happens once construction starts?
- Can a quantity surveyor save you money?
- What could happen if you don’t appoint a QS?
- How much does a quantity surveyor cost?
- Frequently asked questions
What Does A Quantity Surveyor Actually Do?
A quantity surveyor, often abbreviated as QS, manages the financial and commercial aspects of a construction project.
Their role can vary depending on when they are appointed and what support the client needs.
Before construction, a QS may help establish the likely cost of the proposed project, review drawings and specifications, prepare detailed cost information, and assist with tendering.
Once work begins, they can monitor how much has been completed, assess contractor payment applications, review variations, and track how changes are affecting the expected final cost.
At the end of the project, they may also help agree the final amount due to the contractor.
This means a QS can provide financial oversight throughout the project rather than simply preparing an estimate at the outset.
When Should You Appoint A Quantity Surveyor?
Ideally, a quantity surveyor should be involved before major financial commitments are made.
The earlier they are appointed, the more opportunity there is to determine whether the proposed design fits within the available budget.
At the initial design stage, cost planning can help establish a realistic construction budget before the drawings become too advanced. As the design develops, the figures can then be updated to reflect changes in scope, specification and project requirements.
A QS can still be appointed later, though. You might bring one in when preparing to tender, after receiving contractor quotations or during construction if you need support with valuations, variations or costs that are becoming difficult to manage.
At Bhangals Construction Consultants, quantity surveying support covers different stages of the project, including cost planning, tender analysis, valuations, site visits and final accounts. This means the level of involvement can be tailored around where a project currently stands rather than requiring the same service for every client.
Who Is A Quantity Surveyor Useful For?
Quantity surveyors are not only used on major commercial developments. Different clients can benefit from them for different reasons.
Homeowners
A homeowner planning a significant extension, refurbishment or new build may benefit from a QS if they want greater certainty over what the project should cost.
Professional support can be particularly useful when you are receiving several builder quotes and need to understand whether they cover the same work.
The homeowner may also need support managing payments and variations once construction begins.
For very small or simple projects, however, appointing a QS throughout the complete build may not be necessary.
Property Developers
For developers, cost information directly affects project viability and expected return.
A QS can assess construction costs before a project progresses too far, update costs as the design develops and provide commercial oversight throughout tendering and construction.
This can be particularly important on larger residential or commercial schemes where relatively small percentage changes in construction costs can have a significant impact on the overall development margin.
Builders, Contractors And Architects
QS support can also work from the contractor’s side.
Builders and contractors may use quantity surveying expertise to prepare estimates, price tender documents, assess subcontractor costs, manage valuations, and track project profitability.
Architects, meanwhile, often work alongside quantity surveyors so that design decisions can be considered in light of their cost implications.
This can help prevent a project reaching an advanced design stage before the client discovers it has moved significantly beyond budget.
Do You Need A QS For An Extension, Renovation Or New Build?
There is no rule that says every extension or renovation requires a quantity surveyor.
For a relatively simple extension with detailed drawings, a clear specification and a trusted contractor providing a comprehensive fixed price, the additional cost support may be limited.
For larger extensions and renovations, the position may differ.
Existing buildings often contain unknowns. Structural work, services, ground conditions or defects may only become fully apparent once work begins. There may also be several contractor quotations to compare, as well as numerous design choices that affect the final price.
A QS can help bring more structure to these costs.
For a new-build project, professional cost management is often more valuable because the overall financial commitment is greater. A QS can follow the project from early budgeting through contractor selection, construction and final account.
The decision should therefore be based less on whether the project is labelled an extension, a renovation, or a new build and more on its value, complexity, and level of financial risk.
How Does A QS Help Control Construction Costs?
One of the main advantages of appointing a QS is having cost information available at each key decision point.
It usually begins with the budget.
Rather than relying purely on a broad cost-per-square-metre estimate, a detailed cost plan can break the project down into individual elements. This provides greater visibility over where the budget is being allocated and makes it easier to spot areas that are becoming expensive.
When contractors are invited to price the work, a QS can then help determine whether their submissions are genuinely comparable.
Professional tender analysis can identify differences in contractor pricing, allowances, exclusions and assumptions.
This is important because the cheapest tender is not necessarily the best value. A lower price may simply contain less work or more provisional allowances.
What Happens Once Construction Starts?
Cost control should continue after a contractor has been appointed.
Most larger projects involve payments being made as construction progresses. Valuations and site visits can be used to assess progress and establish whether payment applications reflect the amount of work actually completed.
A QS can also monitor variations. Changes during construction can arise from client decisions, design development or unforeseen work. Individually, these costs may appear relatively small, but numerous variations can significantly change the eventual contract value. Monitoring them as they occur gives the client a clearer understanding of the expected final cost.
Once construction is complete, a final account can establish the final financial position, taking into account the original contract value, agreed variations, and payments already made.
Can A Quantity Surveyor Save You Money?
A quantity surveyor cannot guarantee that a construction project will become cheaper simply because they are involved. Their value comes from improving the information used to make financial decisions.
For example, they may identify that a design is exceeding the budget before construction begins, highlight an omission in a contractor’s tender, or challenge a variation that does not appear to be consistent with the agreed contract.
They can also provide greater visibility over where money is being spent. The potential savings, therefore, come from avoiding poor decisions, controlling changes, and identifying financial risks earlier.
What Could Happen If You Don’t Appoint A QS?
Not appointing a quantity surveyor does not automatically mean a project will experience problems.
Many smaller projects are completed successfully without one. However, as the project grows or becomes more complex, managing the finances yourself can become more difficult.
Potential issues can include:
- Setting an unrealistic construction budget
- Comparing contractor quotes that include different scopes
- Missing exclusions or low provisional allowances
- Approving payments without independently checking progress
- Losing track of variations and additional work
- Discovering the likely final cost too late
- Disagreements over the final amount payable
Whether these risks justify professional support will depend on the project and the client’s own level of construction experience.
How Much Does A Quantity Surveyor Cost?
There is no single standard fee for a quantity surveyor. The cost depends on factors such as project value, complexity, the stage at which they are appointed and the services required.
A client who only needs a cost plan or tender review will usually require a much smaller scope of work than someone appointing a QS from early design through to final account.
Fees may therefore be structured as a fixed amount for a particular service or as a fee based on the wider scope of the appointment.
The better question is often whether the level of financial risk on the project justifies the cost of independent advice. On a substantial project, identifying one major omission, overpayment or unnecessary cost can potentially outweigh the professional fee.
You May Need A QS If…
Consider speaking to a quantity surveyor if:
- You are unsure whether your construction budget is realistic
- Your project represents a significant financial commitment
- You are receiving several contractor quotations
- The quotes contain different scopes or provisional sums
- Your design is changing and you need to understand the cost impact
- You are making staged payments during construction
- Variations are beginning to increase the project cost
- You want independent financial oversight
- You need help agreeing the final account
The more of these that apply to your project, the more useful quantity surveying support is likely to become.
Frequently Asked Questions
Is A Quantity Surveyor A Legal Requirement?
Usually, no. Most private construction projects do not legally require you to appoint a quantity surveyor. The decision is generally based on the financial value, complexity and risks involved.
Should I Appoint A QS Before Getting Builder Quotes?
Ideally, yes. Early involvement allows the budget and tender information to be prepared before contractors price the project, making their quotations easier to compare.
Can I Appoint A Quantity Surveyor After Construction Has Started?
Yes. A QS can still help with valuations, variations, cost reporting and final accounts, although appointing one earlier provides more opportunity to prevent cost issues before they arise.
What’s The Difference Between A Quantity Surveyor And An Estimator?
An estimator primarily calculates the expected cost of construction work. A quantity surveyor usually has a broader commercial role, covering areas such as cost planning, tendering, valuations, variations, and final accounts.
Do I Need A QS If I Already Have An Architect?
Potentially. Architects and quantity surveyors have different roles. The architect primarily focuses on the project’s design and technical development, while the QS focuses on costs and commercial management. The two often work alongside each other.
Is A Quantity Surveyor Worth It?
Whether you need a QS ultimately depends on the project.
For a small, straightforward job with a clear scope and a manageable budget, you may decide that professional quantity surveying support is unnecessary.
As project value, complexity and uncertainty increase, however, independent cost management can become increasingly valuable.
Good quantity surveying provides greater visibility from the initial budget through tendering, construction and final account, helping you make financial decisions based on clearer information rather than assumptions.