Retro-commissioning (RCx) is a systematic process that improves a building’s existing operational performance by identifying inefficiencies in how building systems are currently functioning. Unlike new building commissioning, retro-commissioning focuses on existing buildings that were never commissioned or whose performance has drifted over time.
When done correctly, retro-commissioning can deliver measurable energy savings, improved occupant comfort, extended equipment life, and regulatory compliance—often with low-cost or no-cost measures.
Industry studies consistently show that retro-commissioning can achieve energy savings of 5–20%, with many projects realizing payback within 12–24 months, making it one of the most cost-effective energy efficiency strategies available today.
How Retro-Commissioning Works
Retro-commissioning is typically carried out in four structured phases:
1. Planning Phase
This phase identifies which building systems will be evaluated—such as HVAC, lighting, controls, domestic hot water, and ventilation. Project goals, scope, timelines, and data requirements are defined upfront.
2. Investigation & Analysis Phase
Building system operations are reviewed against original design intent and current operational needs. Functional testing, trend analysis, and on-site inspections are performed to uncover inefficiencies and operational gaps.
3. Implementation Phase
Identified deficiencies are corrected, system controls are fine-tuned, and recommended Energy Conservation Measures (ECMs) are implemented. These improvements typically do not require major equipment replacement.
4. Hand-Off & Persistence Phase
Final documentation is prepared, results are reported, and building staff are trained to maintain performance improvements over time. This ensures long-term persistence of energy savings.
Why Retro-Commissioning Is an Investment—Not an Expense
Retro-commissioning should not be viewed as a one-time compliance task. When incorporated as a regular operational best practice, it improves building performance, reduces operational risk, and increases asset value—often paying for itself through energy savings alone.
Key Benefits of Retro-Commissioning
1. Reduced Energy Costs
One of the most immediate benefits of retro-commissioning is lower utility bills. RCx identifies issues such as air leaks, malfunctioning sensors, improper scheduling, and simultaneous heating and cooling—problems that quietly waste energy year-round.
Typical benefits include:
- Improved indoor air quality through optimized HVAC performance
- Better temperature control and occupant comfort
- Reduced energy consumption and peak demand
- Lower maintenance and repair costs
- Extended equipment lifespan
2. Increased Property Value
Energy-efficient buildings are more attractive to tenants, buyers, and investors. Implementing RCx recommendations—such as control optimization, LED lighting upgrades, weatherization, or solar integration—improves a building’s market competitiveness and long-term valuation.
3. Environmental Responsibility
With rising carbon reduction targets and sustainability expectations, retro-commissioning helps building owners actively reduce greenhouse gas emissions. This demonstrates environmental leadership while aligning with NYC’s climate goals and carbon reduction laws.
4. Improved Occupant Comfort & Productivity
Retro-commissioning addresses issues like poor insulation, uneven temperatures, inadequate ventilation, and lighting inefficiencies. Healthier indoor environments directly improve employee comfort, well-being, and productivity, benefiting both occupants and owners.
5. Compliance with NYC Local Law 87
NYC Local Law 87 requires buildings over 50,000 square feet to perform energy audits and retro-commissioning once every ten years as part of the Greener, Greater Buildings Plan.
Core Requirements Include:
- Determining the building’s compliance year
- Conducting an ASHRAE-compliant energy audit and retro-commissioning
- Submitting a complete Energy Efficiency Report (EER) to NYC by the deadline
Failure to comply can result in violations and financial penalties, making proactive planning essential.
The Retro-Commissioning Process Explained
Step 1: Walk-Through Analysis & Interviews
A certified energy auditor conducts a site inspection, performs system testing, collects measurements, and interviews building owners, operators, and occupants. This step typically takes 2–4 hours and provides critical insight into Operations & Maintenance (O&M) practices.
Step 2: Analysis, Reporting & Implementation
Collected data is analyzed to identify inefficient systems and operational issues. The auditor then prepares a detailed report outlining:
- Identified deficiencies
- Recommended ECMs
- Estimated energy and cost savings
Common retro-commissioning measures include:
- Control re-programming
- Repairing or cleaning dampers
- Replacing faulty sensors, actuators, valves, and VFDs
- Optimizing scheduling and setpoints
Most ECMs are low-cost or no-cost, focusing on system optimization rather than equipment replacement.
Retro-Commissioning Cost per Square Foot
Retro-commissioning costs vary based on building type, system complexity, and scope of work. Typical pricing ranges from:
$0.50 to $2.00 per square foot
To control costs effectively, owners should clearly define:
- Project goals
- Data collection requirements
- Expected recommendations and deliverables
Retro-Commissioning Checklist
- Clearly defined objectives and priorities
- Complete building information (size, systems, renovations)
- Trending and monitoring capabilities
- Updated drawings and documentation
- Comprehensive scope of work
- Preferred data acquisition methods
- Phase-wise deliverables
- Energy and cost-saving calculations
- Final reporting requirements
- Defined project cost range
Commissioning vs. Retro-Commissioning
| Commissioning | Retro-Commissioning |
| Applied to new or recently renovated buildings | Applied to existing buildings |
| Verifies design, installation, and performance | Optimizes existing system performance |
| Ensures systems operate as intended | Identifies low-cost O&M improvements |
| Improves efficiency, comfort, and IAQ | Focuses on controls, calibration, and tuning |
Retro-commissioning is a type of building commissioning, specifically designed to optimize existing facilities without major capital upgrades.
Why Choose The Cotocon Group?
The Cotocon Group has a proven track record of delivering Local Law 87 compliance services across New York City. Our experienced team supports building owners through every step of the process—from compliance planning and energy audits to retro-commissioning and Energy Efficiency Report submission.
We help building owners achieve maximum return on investment by demonstrating that energy efficiency is not just compliance—it’s smart business.
