Define level of Cx based on Project risk
- May 30
- 3 min read
In the evolving landscape of building performance and sustainability, commissioning (Cx) has emerged as a cornerstone of quality assurance. As the draft international standard ISO/DIS 24359-1 continues to shape the future of building commissioning, one of its most insightful contributions is the structured approach to defining the level of commissioning based on project risk.
Why Risk-Based Commissioning Matters
Every construction project carries a unique risk profile—shaped by factors such as complexity, intended use, stakeholder expectations, and regulatory requirements. A one-size-fits-all commissioning approach can lead to inefficiencies, either by overcommitting resources or by underestimating critical performance risks.
ISO/DIS 24359-1 introduces a risk-informed framework that helps project teams align the depth and scope of commissioning activities with the actual needs of the project. This ensures that commissioning efforts are proportionate, purposeful, and performance-driven.
A Practical Tool for Risk Evaluation
To support the practical application of this framework, I developed an Excel spreadsheet tool that calculates project risk based on the criteria outlined in ISO/DIS 24359-1. This tool allows users to input project-specific data and receive a recommended commissioning level: basic, intermediate, or advanced - based on a transparent and repeatable scoring system.
The spreadsheet is designed to be:
User-friendly: Simple inputs with clear guidance.
Customizable: Adaptable to different project types and organizational needs.
Aligned with ISO/DIS 24359-1: Reflecting the structure and intent of the draft standard.
This tool empowers project teams to make informed decisions early in the planning phase, ensuring that commissioning resources are allocated effectively and proportionately.
Understanding the Levels of Commissioning
The draft standard outlines a tiered approach to commissioning, where the level of Cx is determined by a combination of:
Project complexity
System criticality
Occupant impact
Regulatory and sustainability goals
Innovation or novel technologies
This allows stakeholders to select from basic, intermediate, or advanced levels of commissioning, each with clearly defined deliverables and expectations.
Level 1 - Basic Cx (Low Risk Projects)
Score between 15-19 points
Ideal for small-scale or low-complexity buildings, this level focuses on verifying that systems are installed and functioning as intended. Documentation is streamlined, and functional testing is limited to essential systems.
The commissioning provider shall be acting independent of the design and construction teams and shall report directly to the owner.
Level 2 - Intermediate Cx (Moderate Risk Projects)
Score between 20-31 points
This level introduces more rigorous planning, documentation, and testing. It is suitable for projects with moderate complexity or where occupant comfort and energy performance are key concerns.
The commissioning provider shall be acting independent of the design teams, shall report directly to the owner, and shall be independent of construction team. The commissioning provider shall not be employed by the contractor(s).
Level 3 - Comprehensive Cx (High Risk or Mission-Critical Projects)
Score between 32-45 point
For hospitals, data centers, or buildings with high sustainability targets, advanced commissioning includes early involvement in design, detailed functional performance testing, and post-occupancy evaluation. This level ensures that all systems interact seamlessly and meet long-term performance goals.
The commissioning provider shall be independent of the design and construction team and shall be contracted directly to or designated by the owner. The commissioning provider shall report directly to the owner. The commissioning provider shall not be employed by neither the design firm(s) nor the contractor(s).
Benefits of a Risk-Based Approach
Optimized Resource Allocation: Focus efforts where they matter most.
Improved Stakeholder Confidence: Clear alignment between project goals and commissioning scope.
Enhanced Building Performance: Systems are more likely to meet design intent and operational needs.
Scalability and Flexibility: The framework adapts to projects of all sizes and types.
Looking Ahead
As ISO/DIS 24359-1 moves toward finalization, its emphasis on planning, transparency, and proportionality in commissioning is a welcome evolution. By defining the level of Cx based on project risk—and supporting it with practical tools like the Excel risk calculator—we can take a strategic step toward smarter, more sustainable buildings.
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