Time takes its toll—on us, and on the labs we work in and depend upon. Keeping our labs, equipment and supporting building systems functioning as designed is critical to accurate and controlled results for work within the lab, operational efficiencies, sustainability, budget control and even occupant comfort. Retro-commissioning is one key to addressing these challenges and more.

In a previous article1, we examined building commissioning—providing an overview and solid grounding into the who, what, when, where, why and how of the commissioning practice. This article will examine retro-commissioning—also known as existing building commissioning—which, as defined on the ACEEE (American Council for an Energy-Efficient Economy) website, is a systematic process for identifying and implementing operational and maintenance improvements in a building to ensure continued good performance over time. This is a common definition throughout the industry. 


So, let’s first tackle a question many of you may have in your minds: “Why should I care?” If you care about any of the following benefits offered by retro-commissioning, you’ll want to read on: 

•    Improving the functioning of your labs, buildings and key equipment which can simplify the re-certification process, if applicable
•    Reducing your energy and operations costs while reducing your energy consumption
•    Reducing your facility’s carbon footprint
•    Reducing downtime in labs and buildings while increasing operational efficiencies
•    Minimizing maintenance calls (and associated costs) to the facilities department or outside vendors
•    Identifying code violations before they become an expensive legal headache
•    Ensuring optimization of building and lab equipment, while reducing wear and tear that diminishes equipment lifecycles
•    Increasing your organization’s CSR (Corporate Social Responsibility) score, often important to academic, venture capital, investors and corporate entities
•    Enhancing the safety and health of your facility’s users
•    Improving the comfort of lab users—an impact which is becoming more critical as the competition for talent continues to escalate
•    Identifying either malfunctioning or less than optimally operating equipment, sensors and building systems
•    Understanding the potential to leverage newer technologies developed since your building first came online, with operational, cost and energy implications
•    Proactively identifying and developing a multi-year plan to address deficiencies in your lab or building, in the spirit of avoiding unwelcome and costly surprises
•    Gaining a firm understanding of the costs of continued deficiencies, corrective actions and the payback period of alternate options
•    Improving your LEED, Green Globes, Energy Star or other ratings if your facility is involved in any of these programs
•    Identifying and receiving potential financial grants to make critical improvements

Underlying all of above is the goal of your commissioning professional to find solutions (to any issues uncovered) that are reasonable to execute, and cost-effective when measured against payback periods, benefits and avoiding costly problems. 


The investigation and end report—as well as suggested remedial actions—need to be completed efficiently and accurately. Engaging a certified commissioning agent (CxA) denotes a high level of expertise. The additional designation of certified energy manager (CEM) requires further expertise. Working knowledge of the laboratory environment, the systems that support it and the complexities of the equipment interplay round out the required skill set. The commissioning agent functions as a catalyst and critical link between all parties with a stake in how the building or lab functions. 


It’s worth repeating, to dispel some common engineering myths, that building commissioning is not a value engineering exercise. A competent commissioning agent will work with the team during the investigation and implementation phases, including the facilities department, original design engineers (when available), contractors and other stakeholders, to ensure accurate and complete information gathering and documentation. A team approach is also important to ensure efficient execution. Building commissioning is not a “blame game,” but rather a solution seeking process.


In my earlier article from January/February 2017, the commissioning process overview took a look at the ASHRAE Guidelines to define the commissioning process, which is generally broken down into the Design Phase, Construction Phase, Acceptance Phase and Post-Occupancy Phase and Continuous Commissioning. Given that retro-commissioning is focused on previously constructed and operating buildings and labs, a common way to segment the process is in three steps, with subsections, following proposal acceptance and depending on the scope of work identified in the contract:

The Planning Phase: Some hallmarks of the planning phase include an initial site visit and survey, review of existing documentation, including utility records, design documents and system specifications. Discussions of perceived issues, performing an energy and systems audit to inform the identification of energy issues and potential remedial actions, further investigation into operations and the development of an issues log lead to the development of a detailed work plan.

The Investigation Phase: During the active investigation, the CxA will be focused on monitoring and testing, while working with facilities staff to ensure the implementation plan meets the facility’s needs, their budget requirements and the expectations and skillsets of the facility staff. The CxA always remains focused on the ultimate end goal: optimizing facility and building systems performance. The final implementation plan may include suggested remedial actions that are both prioritized and phased.

A baseline of current building systems and equipment performance will be established, and examined against the original operating specifications. A detailed monitoring and testing process is developed, and functional testing (including testing of specialty lab equipment, such as hoods) is undertaken. Sometimes seasonal testing needs to take place in order to develop an accurate baseline of building system functionality through a full year. 

Throughout the process, it’s critical for the commissioning agent to stay engaged with the facility staff, keeping them informed of the project status while discussing issues uncovered by testing and monitoring, as well as potential corrective actions and systems changes. The commissioning agent will identify energy conservation opportunities and prepare a draft report. Additional design support and cost estimating may be important components of the report recommendations as they can guide the next steps if corrective work or the application of enhanced systems features that are viable for consideration.

The Implementation Phase, and Client Hand-off: Client “hand-off” is a bit of a misnomer—as noted in the article opening, time takes its toll on the ability of labs and building systems to operate within their design parameters. Ideally, building owners and facilities professionals implement a program of continuous commissioning, on a mutually agreed-upon schedule developed with consideration to equipment and building system sensitivities, operating parameters and impacts on operations when functionality is out of alignment with requirements. 

In this phase, to coin a well-known saying, “the rubber meets the road.” During the implementation stage of the project, the commissioning agent will detail both the scope and estimated costs of any capital improvement projects, including equipment replacement. Measurement and verification will be undertaken, and the final retro-commissioning report will be produced. 

An important part of any retro-commissioning undertaking is training the facilities staff, but staff from operations and EH&S (environmental health and safety) departments should be included as well, depending on responsibilities and functions within an organization. Aligning equipment and operations processes with the original design intent is all for naught if, for example, a single operations person decides to override air handling sequences or temperature control settings. Developing a strong, ongoing staff training program is a cost effective way to help ensure building systems and equipment continue to operate within design parameters as long as possible, and obviate problems before they develop. 

A final retro-commissioning report will be written, with recommendations for future maintenance and capital improvement projects. During implementation, selected modifications will be executed, based upon agreement with the owner’s representative regarding priorities, budget and operations factors. 

“What you can’t measure, you can’t manage” is often cited to reinforce the importance of testing improvements against original goals. Verify, verify, verify—and to get there, measurement is your best friend. Slippage of performance metrics often happens slowly and insidiously, an erosion of performance over time often not noticed—nip that early on with ongoing monitoring and measurement. Investigating a lab’s building automation or management system—BAS or BMS—and how quickly functional changes in the lab environment are detected and reported can provide facilities professionals with a clear understanding of how the lab functions. 


Labs have earned a notorious reputation as energy hogs. The sources contributing to this bad rap are numerous and insidious. Some issues are controlled by human behavior, such as redundant and unnecessary lab freezers, or overriding airflow, temperature and ventilation controls. It’s not uncommon for a lab’s airflow supply to be heated and cooled, at the same time and not intended by design. While we’re on the subject of air flow, let’s consider exhaust: are the dampers functioning and adjusted properly? Is air leaking anywhere in the system? How is that variable speed drive (VSD) calibrated and operating? Do you have an energy recovery system, and is it functioning as specified? Is your lab ventilation excessive? Has the room or building envelope been modified through follow-on construction activities and the airtightness compromised? When the lab isn’t occupied, can it utilize a setback mode for both airflow and temperature, without compromising required environmental conditions for work or samples? Hoods have their own challenges, including but not limited to: inappropriate hoods for the function, excessive airflow specifications, spillage, underutilization, manual override of exhaust, sash position and over-sized bypass openings. Chapters have been written on energy challenges associated with fume hoods, although new developments and customized hoods are being deployed more frequently in today’s specialty labs. 

A lab retro-commissioning process can address equipment issues, as well as building infrastructure issues, to maximize both energy and the bottom line, monetary savings. 

Labs are complex environments—and retro-commissioning can eliminate many performance problems while saving money and energy. Specialty gases, toxic liquids, detailed environmental parameters under which the lab must operate (including particle controls, air purity, temperature and humidity ranges, airflow volumes, pressurization), and specialty waste systems and disposal requirements complicate the demands. 

Retro-commissioning offers a best bet option to stay ahead of systems, building and operations degradation. It’s not unusual for retro-commissioning payback periods to range from under a year to three years, depending on cost and complexity. When calculating the ROI of a retro-commissioning project, it’s wise to also include additional savings such as reduced maintenance and downtime, more productive lab employees due to a more comfortable environment (and improved lab environments are important recruiting tools in today’s competitive science field), and improved health and safety.


Additional references
The Building Commissioning Association (BCxA): 

Mike Chonko, PE, CEM, directs mechanical engineering at SMRT Architects and Engineers. A Certified Energy Manager and licensed mechanical engineer, Mike has more than 20 years’ experience solving complex challenges for clients in science/technology/industry, healthcare, government, justice and education. His passion: developing energy systems that are operationally and financially sound, yet highly efficient.;