DC’s Building Energy Performance Standards (BEPS) are here. Building owners, operators, and their service providers are working together to identify and implement energy efficiency measures to comply. During BEPS Period 1, over 800 buildings are non-compliant with the regulation and will need to take action towards improving efficiency. Over time, it is expected that the rigor of BEPS will increase, potentially requiring further improvements and highlighting the value of persistent efficiency improvements. The Department of Energy and Environment’s (DOEE) Cost and Benefit Impact Study found that for most building types, retro-commissioning is either the first or second most cost-effective measure to reduce operational energy use—the energy that is used during the occupancy stage of a building’s life cycle. This is inline with previous research by Lawrence Berkeley National Laboratory and the Building Commissioning Association and guidance assembled by the Environmental Protection Agency’s Energy Star program. While the retro-commissioning guidance included here refers to BEPS, it is intended for any building looking to improve its operations or comply with performance standards in other jurisdictions.
What is Retro-Commissioning?
Retro-commissioning (RCx) is a systematic process to evaluate and improve an existing building’s energy performance by:
- testing systems and equipment
- identifying measures for implementation
- implementing changes
- training owners and operators how to take advantage of modified systems and equipment
The process starts with documenting Current Facility Requirements (CFR) which include building-specific operating parameters, and performance and financial goals. Then, an RCx Plan is created to guide the process; it identifies which systems will be tested and what steps will be taken to perform those tests, along with other information to manage and communicate the process.
After that, functional tests are performed on the building systems. The results of functional testing are used to identify issues and develop measures for implementation. Some measures will involve simple operational changes like space temperature set points or equipment operating schedules. Others will be more involved, like converting a hydronic loop to variable flow, opening pump throttling valves or using variable frequency drives (VFD) to control loop flow. The identified measures are screened for cost effectiveness, expected service life, and impact on building performance.
Owners are given these results to select packages of measures that can be implemented or budgeted for implementation in future years. As measures are implemented, the measures are verified, tested, and evaluated. The building operating staff are then trained, and turnover documentation is generated. Finally, the change in building performance is documented and lessons learned are fed forward to the next cycle of performance improvement for a building. This process is outlined in more detail in our downloadable scope of work, and we have created a sample CFR template and a sample Retro-Cx Plan template for download.
Retro-commissioning, also known as Existing Building Commissioning (EBCx), is an approach that has been around for decades. In New York City, for example, Local Law 87 enacted in 2009, requires a highly prescribed retro-commissioning effort for large buildings every 10 years with definitive testing requirements. In DC, the BEPS prescriptive pathway requires examination of HVAC, lighting, domestic water, envelope, commercial kitchens, and building management systems but offers flexibility to building owners on how to conduct tests and trend reviews, including retro-commissioning.
Washington D.C. is not alone in their development of building performance standards (BPS) policies. The National BPS Coalition, launched by President Biden, represents cities, counties, and states across the US that have committed to inclusively design and implement building performance policies within their jurisdictions. In total, more than 25% of both the US population and building square footage reside in jurisdictions considering BPS policies. Learn more from the Institute for Market Transformation about the jurisdictions that have passed BPS.
In collaboration with these efforts the US Department of Energy and Lawrence Berkeley National Laboratory are in the beginning stages of launching the EBCx Catalyzer initiative, with the fundamental goal of fostering and expanding building commissioning services throughout the BPS compliance life-cycle. This initiative will provide tailored resources, training and engagement within BPS regions to promote cost-effective energy/carbon reductions as the ‘tip of the spear’ towards long-term, high-performance, and low-carbon buildings.
Bringing Retro-Commissioning to My Building
Is retro-commissioning valuable for all buildings? It really depends. A few building features that may increase the impact of a retro-commissioning process are:
- HVAC prime movers that have at least five years left in their expected life
- Stable occupancy
- A direct digital control (DDC) system
- Regular maintenance needs like filter and belt changes and corrosion control
- The ownership team wants technical assistance to create a road map to prioritize potential measures and gain the most value out of their asset.
Identify your building’s goals. Is the goal to cost effectively comply with BEPS? Are there ongoing operational issues needing to be addressed? Consistent comfort complaints requiring an outside collaborator to close?
Using the specific building goals as context, identify a budget. The budget should include two parts: first planning and investigation then implementation. In part one, a retro-commissioning plan is created, functional tests are conducted on-site, and measures are identified for consideration. Part two is implementation and turnover. In part two, measures or packages of measures are implemented, turnover documentation is produced, training is conducted, and the performance results of the process are evaluated.
Assemble building documentation. Some of the first bits of information that retro-commissioning providers will ask for include drawings, reports, energy performance data, and Current Facility Requirements. Having these documents digitized and organized is recommended to streamline the process, as it will enable a potential retro-commissioning provider to focus on building performance instead of tracking down drawings.
Bring a retro-commissioning provider on board and begin the work. As a companion to this blog post, we have developed a downloadable template scope of work that you can use to procure RCx services. Qualification-based procurement is always recommended for commissioning services.
The Building Innovation Hub, DC Sustainable Energy Utility (DCSEU), and the DOEE are resources to help identify a retro-commissioning service provider in the DC Metropolitan area. Some qualifications that indicate a professional has training and experience in retro-commissioning include but are not limited to:
- ASHRAE Building Commissioning Professional (BCxP)
- Building Commissioning Association Certified Commissioning Professional (CCP)
- AEE Certified Building Commissioning Professional (CBCP)
- Existing Building Commissioning Professional (EBCP)
A good provider will also assist in evaluating the potential incentives in the marketplace. At the time of this writing, pay-for-performance incentives are available from DCSEU to reduce the cost of retro-commissioning efforts and implementing retro-commissioning findings.
Project Highlight: Public Charter School Ventilation
Retro-commissioning is taking place all over DC right now as part of building owners’ and operators’ efforts to comply with BEPS. While these efforts are still underway, here is an example from a recent project highlighting benefits of retro-commissioning.
A public charter school building in Northeast Washington, DC was being renovated in phases. To assess how existing building systems and newly added equipment interacted and identify opportunities for operational improvements, existing to remain systems were retro-commissioned. Results included updated DDC-system graphics and the finding that heating was never provided to an existing rooftop unit and that this lack of heat meant no ventilation for two floors of classrooms anytime temperature were less than 45°F. Collaborating with the building operator, the retro-commissioning provider was able to document the issue and bring out the original installing contractor to connect a gas line and confirm heating operation. Finding long-buried or forgotten issues is one key benefit of retro-commissioning.
This example is instructive because the measure that was identified and implemented corrected a condition that had been present for five years. In this case, the measure likely resulted in an increase in energy use—but also fixes a major operational performance and indoor air quality issue.