Introduction To The Feasibility Stage

Section 1

Purpose

The Feasibility Stage corresponds to RIBA Stage 1 (Preparation and Brief) and represents the point at which the QS first engages meaningfully with the project following appointment. Its primary purpose is to test whether the proposed project is financially viable before significant design expenditure is committed. The QS’s role is to translate the client’s brief into cost terms, establish a realistic cost range for the project, identify and quantify key risks, and advise on the most appropriate procurement route.

Cost advice at this stage is governed by RICS NRM 1: Order of Cost Estimating and Cost Planning for Capital Building Works (2nd edition, reissued as practice information October 2022). The RICS Cost Prediction Professional Standard (Global, 1st edition, reissued June 2024) further imposes mandatory obligations on how cost predictions are communicated — including the requirement to disclose the basis of the estimate and its expected accuracy range.

Decisions made at feasibility shape every subsequent stage of the project. An underfunded budget, an unidentified site constraint, or the wrong procurement route chosen here will create problems that are far more expensive and disruptive to resolve once design has advanced. Getting the feasibility stage right is one of the most valuable services a QS provides.

Section 2

Key Principles

RICS NRM 1 is the governing standard for Order of Cost Estimates at feasibility. It defines the methods (floor area method, functional unit method, elemental method) and sets out what must be included, excluded, and disclosed.
The RICS Cost Prediction Professional Standard (reissued June 2024) is mandatory. It requires QS practitioners to disclose the basis of any cost prediction and its expected accuracy range. A cost estimate presented without these disclosures is non-compliant.
Always present cost advice as a range, not a single-point figure. At feasibility stage, the level of design information does not support false precision. A range with clearly stated assumptions and exclusions is both more honest and more defensible.
Feasibility study and cost planning are distinct activities. A feasibility study is a high-level viability test using cost/m² benchmarks or functional unit rates. Cost planning is the structured, detailed process that follows — evolving through NRM 1 elemental breakdowns across Stages 2, 3, and 4.
BCIS (Building Cost Information Service) is the primary benchmarking tool for UK construction. Any benchmark rate must be adjusted for location (regional index), time (Tender Price Index), specification uplift/reduction, and project-specific abnormals before use.
Optimism bias — the systematic tendency to underestimate costs and overestimate benefits — must be explicitly addressed in the feasibility cost estimate. Failure to account for optimism bias is a common cause of budget inadequacy as projects develop.
The project risk register is established at feasibility and maintained throughout the project life. At RIBA Stage 1, a risk/design contingency of 10–15% is typically appropriate, reducing to 7–10% at Stage 2 and 3–5% at Stage 3 as risks are resolved.

Section 3

Practical Application

Follow these steps when the feasibility stage is triggered post-appointment:

Step 1

Review and confirm the project brief in writing. Identify the building type, GIFA, quality specification, budget envelope, programme milestones, sustainability/ESG targets, and funding arrangements. If the brief is unclear or contradictory, document your interpretation and circulate to the client/PM for written confirmation before proceeding. An undocumented brief is a source of future dispute.

Step 2

Undertake a site appraisal — identify and cost constraints. Consider ground conditions and contamination risk, topography, access/logistics, existing services, planning restrictions, flood risk, and party wall obligations. Request Phase 1 Environmental Survey data where available. Include a ground risk allowance in the estimate and recommend an early site investigation.

Step 3

Prepare the Order of Cost Estimate in accordance with RICS NRM 1. Select appropriate cost/m² or functional unit rates from BCIS, adjusted for location, time, and specification. Build up: Measured Works + Preliminaries (12–18%) + Contractor OHP (4–8%) + Design Contingency (10–15%) + Inflation + Fees. Identify and price known abnormal costs separately. Present as a range with stated assumptions, exclusions, and the accuracy range required by the Cost Prediction PS.

Step 4

Prepare cost analysis and benchmarking data. Define the purpose and scope of the analysis. Record key project metrics (GIFA, NIA, wall-to-floor ratio, number of storeys, sector, construction type, sustainability rating). Record TPI and location factor. Flag abnormal costs clearly so they do not skew elemental comparisons. Obtain employer's consent before using project data for benchmarking purposes. Where multiple design options are under consideration, prepare cost models to compare their financial implications — for example, structural frame alternatives (steel vs concrete), sustainability rating targets (BREEAM Very Good vs Excellent), or specification level variations. Cost modelling at feasibility stage is low-cost and high-value: it informs client decisions before significant design investment is committed.

Step 5

Establish the project risk register using the RICS Management of Risk framework: Identify → Categorise → Assess (Probability × Impact) → Respond (Avoid / Reduce / Transfer / Share / Retain) → Allocate (named owner) → Quantify (expected monetary value or Monte Carlo simulation) → Monitor. Address optimism bias explicitly as a risk category.

Step 6

Prepare a procurement options appraisal. Set out the main routes (Traditional, Design and Build, Two-Stage Tendering, Construction Management/Management Contracting) with their advantages and disadvantages relative to the client’s stated priorities (cost certainty, programme, risk appetite, design control, market conditions). Make a written recommendation. The client’s decision should be recorded in writing. Refer to RICS Developing a Construction Procurement Strategy.

Step 7

Issue the feasibility report to the client. The report should include the Order of Cost Estimate (as a range), basis of estimate, stated assumptions and exclusions, accuracy range per Cost Prediction PS, risk register summary, procurement recommendation, and any programme observations. Retain a signed or acknowledged copy on the project file.

Section 4

Common Mistakes to Avoid

Presenting a single-point cost figure without a range and stated assumptions. This is non-compliant with the RICS Cost Prediction Professional Standard and misleads the client about the inherent uncertainty at this stage.
Failing to address optimism bias explicitly. Budgets that do not account for systematic underestimation will be found inadequate as the project develops, creating credibility problems for the QS.
Not documenting the project brief in writing before preparing the cost estimate. If the brief changes and the estimate changes with it, you need a documented baseline to show why.
Omitting abnormal costs or failing to flag them clearly. Abnormals such as piled foundations, contamination remediation, or complex access must be included in the estimate and clearly identified — not hidden within elemental rates where they will distort future benchmarking.
Recommending a procurement route verbally or informally without a written appraisal and recorded client decision. The procurement choice is one of the most consequential decisions of the project — it must be documented.

Section 5

APC Competency & Quick Reference

This guidance note is relevant to the following RICS APC competencies: Cost Management (, Levels 1–3); Procurement and Tendering (, Levels 1–2); Risk Management (, Levels 1–2); Data Management (, Level 1).

What is an Order of Cost Estimate and when is it prepared?

It is prepared at RIBA Stage 1 (Feasibility) per RICS NRM 1 when design information is minimal. It provides a cost range for the project based on floor area or functional unit rates, adjusted for location, time, specification, and known abnormals. It must be presented as a range with explicit assumptions, exclusions, and an accuracy statement per the RICS Cost Prediction Professional Standard.

What contingency allowance should be carried at feasibility stage and how does it change as the project develops?

At RIBA Stage 1, a risk/design contingency of 10–15% is typically carried within the cost estimate. This reduces as design develops and risks are resolved: typically 7–10% at RIBA Stage 2, 3–5% at Stage 3. The contingency should be reported transparently — clients must understand what it covers.

What are the main factors to consider when advising a client on procurement route at feasibility?

Key factors are: (1) degree of cost certainty required; (2) programme priority and whether an early start is needed; (3) completeness of design before going to market; (4) client’s capacity and appetite to manage risk; (5) complexity and specialist content of the project; (6) market conditions and tenderer availability. Refer to RICS Developing a Construction Procurement Strategy.

Section 6

Feasibility Stage Checklist

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Project brief reviewed, interpreted, and confirmed in writing to client/PM

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Site appraisal completed — constraints, abnormals, and ground risk allowance identified and costed

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Order of Cost Estimate prepared in accordance with RICS NRM 1 — presented as a range with assumptions and exclusions stated

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RICS Cost Prediction PS accuracy range disclosed and documented

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Optimism bias assessed and explicitly addressed in the cost estimate

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Project risk register established — risks identified, categorised, assessed (P×I), and contingency quantified

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Procurement options appraisal prepared — written recommendation issued and client decision recorded

Section 7

CPD Learning Outcomes

Prepare an Order of Cost Estimate in accordance with RICS NRM 1, selecting appropriate benchmark rates and applying correct adjustments for location, time, specification, and known abnormals.
Establish a project risk register using the RICS Management of Risk framework, quantifying contingency allowances appropriate to the stage of design.
Produce a procurement options appraisal setting out the advantages and disadvantages of available routes relative to the client’s stated priorities, and issue a written recommendation.

Section 8