When should I appoint a Quantity Surveyor?
The short answer is: appoint a Quantity Surveyor while there is still time to influence the design and budget.
For most construction projects, this means bringing a QS into the team during the early design stages—ideally before the design has been finalised or submitted for planning.
A Quantity Surveyor can still provide valuable support later, including during tendering or after construction has started. However, the later the appointment is made, the fewer opportunities there are to prevent budget problems before they arise.
Early cost advice is usually more valuable than late cost reporting.
Why does the timing matter?
Construction costs are influenced by decisions made throughout the design process.
The size and shape of the building, structural approach, materials, finishes, building services and programme will all affect the eventual cost. Individually, some decisions may appear relatively minor. Together, they can move a project significantly above or below its available budget.
The earlier a QS is appointed, the easier it is to:
Establish whether the initial brief is affordable
Compare different design options
Identify the main cost risks
Set appropriate allowances for uncertainty
Keep the developing design aligned with the budget
Make changes before substantial design work has been completed
Once a project has received planning permission or progressed into detailed technical design, changing direction can become more difficult. The client may have become attached to the design, while the architect and other consultants may need to revisit work they have already completed.
The project can still be adjusted, but the process is likely to involve more time, expense and frustration.
What is the ideal stage to appoint a QS?
Ideally, a Quantity Surveyor should be appointed once you have an initial project brief and enough information to understand what you are considering—but before the design becomes fixed.
This could be as early as:
Identifying the approximate size and scope of the project
Reviewing an initial architect’s sketch or concept design
Testing whether a site or building presents a viable development opportunity
Establishing a preliminary budget before purchasing a property
Comparing refurbishment, extension and new-build options
At this stage, the cost advice will necessarily be based on assumptions and limited information. It will not be a final tender price.
However, an early cost appraisal can still answer the most important initial question:
Is the project you are considering broadly compatible with the money available?
As the drawings and specifications develop, the QS can update the cost plan and replace early assumptions with more detailed information.
Should I appoint a QS before planning permission?
In many cases, yes.
Planning drawings can establish important aspects of the project, including its size, massing, external appearance and relationship with the existing building. These decisions can have a significant effect on cost.
Obtaining cost advice before submitting the planning application gives you an opportunity to adjust the design while it is still flexible.
If you wait until planning permission has been granted, you may discover that the approved design exceeds the available budget. Changing it could require additional design work and, depending on the changes, a revised planning application.
This does not mean that every planning submission needs a detailed cost plan. The appropriate level of work will depend on the project. For some clients, a relatively simple early estimate may be enough to identify whether the design is moving in the right direction.
The estimate can then be developed into a more detailed cost plan as the project progresses.
What if I already have planning permission?
You have not missed the opportunity to appoint a Quantity Surveyor.
Once planning permission is in place, the design will normally progress into more detailed technical information. This is another important stage for cost management.
A QS can:
Prepare or update the cost plan
Review the developing technical design
Identify information that contractors will need to price
Advise on risk and contingency allowances
Suggest areas where alternative solutions could be explored
Prepare tender documentation
Help establish the proposed procurement and contract arrangements
The important point is to complete this work before inviting contractors to tender.
A common mistake is to treat the tender process as the first proper test of the budget. By then, the design may be substantially complete and the client may have spent considerable time and professional fees developing it.
If the returned tenders are significantly over budget, the project may then require a rushed value-engineering exercise. This can result in compromises being made under pressure rather than through considered design decisions.
Can I wait until I have contractor prices?
You can appoint a QS to review contractor tenders, and this can still be extremely useful.
Contractor submissions are not always directly comparable. One may have included work that another has excluded. Provisional allowances, qualifications and differing interpretations of the drawings can also make the apparent lowest price misleading.
A QS can analyse the tenders, identify these differences and help establish a more realistic comparison.
However, appointing a QS after receiving tenders limits what they can do about the underlying design. At this stage, the focus may be on explaining why the project is over budget and identifying reductions rather than preventing that situation from developing.
In my experience, some of the most difficult project conversations happen when a carefully developed design reaches tender and the lowest credible price is substantially above the client’s budget.
That is why the tender should ideally confirm a well-tested cost plan—not reveal the likely project cost for the first time.
What if construction has already started?
It is still possible to appoint a Quantity Surveyor after work has commenced.
A QS may be able to help with:
Reviewing the agreed contract sum
Establishing the current financial position
Assessing applications for payment
Reviewing variations and additional costs
Creating a variation register
Forecasting the likely final cost
Advising on disputed or unclear contractor charges
Negotiating and agreeing the final account
However, the quality of the available records becomes particularly important.
If work has started without a clear scope, detailed contract sum or agreed process for valuing changes, establishing the correct financial position may take time. There may also be commitments and decisions that can no longer be changed.
At this stage, the QS is helping to introduce control and clarity. They cannot undo costs that have already been committed.
Is it ever too early to speak to a QS?
It is rarely too early to have an initial conversation.
You do not need complete drawings before approaching a Quantity Surveyor. Early discussions can help you understand:
What level of cost advice is currently possible
What information will be required
When a formal cost plan should be prepared
What allowances should be included in the initial budget
Whether the proposed programme is realistic
What QS services the project is likely to require
You may not need a full appointment immediately. A limited feasibility estimate or initial budget review might be the appropriate first step.
The QS can then become more involved when the design reaches the point where detailed cost planning will add greater value.
Warning signs that you need cost advice now
You should consider speaking to a Quantity Surveyor if:
Your architect is developing the design without an agreed construction budget
You have a fixed maximum amount available
Your initial budget is based mainly on a cost-per-square-metre assumption
The design has changed significantly since the original estimate
You are approaching a planning submission without testing affordability
You are preparing to invite contractors to tender
Contractor quotations contain substantial exclusions or provisional sums
Variations are accumulating during construction
You are unsure how much the completed project is likely to cost
The project is being funded by a lender, investor or board of trustees
The presence of one of these issues does not automatically mean that you need a full QS appointment. It does suggest that obtaining independent cost advice would be sensible.
What information should I send to a Quantity Surveyor?
Send whatever reliable information is currently available. This might include:
Architectural drawings
A written project brief
Proposed areas or accommodation schedules
Planning documents
Structural or building-services information
Surveys and reports
Outline specifications or schedules of finishes
Contractor quotations
Your intended programme
Details of the available budget
Any known site constraints or project risks
Do not delay the initial conversation because some of this information is unavailable. The QS should be able to explain what can be achieved using the current information and what will be required for the next stage.
So, when should you appoint a Quantity Surveyor?
For most substantial construction projects, the best time is during the early design stages and before the design is fixed.
This gives the project team the greatest opportunity to align the brief, design and budget while changes can still be made relatively easily.
If the project has already progressed beyond that point, cost advice can still be valuable. A QS can review the design, analyse tenders, establish financial controls or help bring clarity to a project already under construction.
The service simply changes as the project progresses:
Early appointment helps prevent cost problems. Later appointment helps manage the position that already exists.
If you are unsure whether your project is ready for QS input, Tantallon Projects offers an informal initial conversation. We can review where you are in the process, explain what cost advice is currently possible and tell you honestly whether you need support now or at a later stage.
