When to appoint a Quantity Surveyor?

Many clients assume a Quantity Surveyor is only needed once a project is on site.

In reality, the earlier a QS is involved, the greater the impact on cost certainty, value, and overall project success.

At Tantallon Projects, most of the value we add happens long before construction begins.

The Short Answer

The best time to appoint a Quantity Surveyor is before detailed design is finalised and before a Building Warrant or tender process begins.

This allows informed decisions to be made while changes are still cost-effective.

Where a QS Adds Value

Early Design & Feasibility (RIBA Stages 1–2)

At concept stage, a QS can:

  • Provide order-of-cost estimates

  • Test affordability of the brief

  • Align expectations with budget

  • Highlight major cost drivers early

This prevents designs progressing beyond realistic budgets.

Developed Design (RIBA Stage 3)

This is when many clients engage us.

Typical support includes:

  • Elemental cost plans

  • Detailed cost breakdowns

  • Identifying high-cost areas

  • Value engineering advice

  • Budget refinement before technical design

This stage often delivers the biggest savings.

Technical Design & Pre-Construction (RIBA Stage 4)

Here we help to:

  • Prepare pre-tender estimates

  • Advise on procurement routes

  • Manage tender processes

  • Ensure value for money

Construction Stage (RIBA Stages 5–6)

During construction we provide:

  • Cost control and reporting

  • Variation assessment

  • Payment certification

  • Final account agreement

This protects clients from cost overruns and disputes.