Best Practices For Decommissioning To Recommissioning Your Buildings

In response to COVID-19, you may have closed your buildings quickly. Did you properly decommission your building and its systems?

Jeffrey H. Peters, P.E., MAC, CEICC

If COVID-19 gave you an empty building, you should now be considering what you need to do when it is full again. Before building occupants come back, you need to make sure you have taken advantage of the shutdown. You may have closed your building quickly, hoping this was only for a few days, and now it looks like it could be weeks or even months. When you shut your building down, did you prepare for being off-line for this long? Did you properly decommission?

(Photo: Getty Images/EyeMark)

Decommissioning consists of an orderly shutdown of the building’s systems and preparing the building for long term dormancy, also called “mothballing.” You will also need to consider recommissioning, which consists of restarting your systems and assuring they are running optimally as originally intended before you turned everything off.

Environmental Concerns

The term mothballing may be particularly relevant for a shutdown. Now most building owners and managers will not need to worry about “moths” per se, but what about mold growth? Environmental conditions within the building need to be considered, especially controlling high humidity conditions. Mold will grow whenever relative humidity (RH) exceeds roughly 65% for an extend time (more than 100 days). The higher the RH the quicker the mold growth (an RH over 80% can cause mold growth in as little as 10 days). Maintaining humidity control in your building should be considered, watching for stagnant low airflow locations (closets, storage rooms, etc.) for mold growth. Running the heating, ventilating and air conditioning (HVAC) systems periodically to maintain RH below 60% and provide air circulation would be prudent.

Photo: Jeff Peters at Rimkus Consulting Group

While you are considering environmental contamination, what about the SARS-CoV-2 virus that causes COVID-19? We are still learning things about this virus and how it behaves in a building. However, the current understanding of the virus’s viability (ability to make a person sick) appears to be approximately three hours in the air, and up to 72 hours on surfaces.¹ Fortunately, if your building has been closed for several days, and possibly weeks, the virus should no longer be viable in the air or on surfaces. Periodic running of the HVAC systems, using as much fresh air as possible, will help purge the building and will also aid in reducing any odor build up. Also, just before opening would be a good time to change out your filters.

Plumbing Systems

For your plumbing systems you should consider whether the shutdown will last until freezing conditions might occur. Therefore, plumbing valves should be closed to prevent any inadvertent leak from causing damage. However, pipes with valves closed still have water in them, so they still need to be protected from freeze damage or you should consider draining water from the pipes. You also should consider that your traps will dry out (typically in about 30 day or so) and can cause bad odors in your building. The traps can be kept primed by adding water periodically or by applying a thin film of vegetable oil on top of the water to keep it from evaporating.

A building’s fire protection system needs to be monitored during a shutdown and should remain active. If you contemplate turning off the fire protection due to freeze protection concerns, you will need to discuss this with the Fire Marshall. The National Fire Protection Association (NFPA) requires that heat must be maintained above 40 degrees Fahrenheit, which is another good reason to keep the HVAC systems running, at least at minimal temperatures.

When you return the potable drinking water systems will need to be flushed. Stagnant water may be a source of water borne bacteria, such as Legionella and others hazards such as metal contamination from high levels of leaching lead or copper. Therefore, stagnant water should be purged from your pipes. That would include all sinks, showers, drinking fountains, ice makers, coffee makers, hot water storage tanks, cooling towers, etc. This would also be a good time to service your pumps and motors to make sure they are lubricated after an extended down time. You may also need to contact your health department to get an all clear from them before the plumbing can be used again.

Photo: Jeff Peters at Rimkus Consulting Group

Electrical Systems

Your electrical systems are probably seeing substantially reduced loads at this time, but with low loads, or areas completely shut off, this might also be a great time to perform those long deferred preventative maintenance projects or repairs. In many areas, contractors are still allowed to perform repairs and maintenance. Tighten connections in panel boards, clean dusty switch gear internals, or enter electrical vaults and service equipment that has not been turned off in years. Also remember to continue to test and exercise your emergency generators to keep them ready to go.


Secure openings into the building, perhaps reinforcing most entrances to reduce to one singular access point. Consider periodic walk throughs (daily or maybe weekly) to address any new issues (roof leaks, break ins, etc.). Camera systems should be reviewed, is data saved off site or will it need to be periodically transferred from onsite digital storage (typical limits of 30 days or so) to offsite storage? Security as well as fire alarm systems will need to remain operational while the building is unoccupied. Do not turn off fire alarms without discussing with the local authority having jurisdiction (AHJ) and checking with your insurance carrier.

The practices for shutting down and restarting an elevator are determined by the American Society of Mechanical Engineers (ASME) A17.1 Safety Code for Elevators and Escalators or the local elevator safety code. For this reason, it is desirable that the applicable local elevator safety commission be contacted to ensure that the procedures for that jurisdiction are followed for shutting down and restarting.

Your building may not have ever been shut down for this long before, so be vigilant for systems that could be stressed after being idle when they are restarted. These are challenging times, but also present an opportunity to take advantage of the time to get some maintenance done, or possibly a deep thorough cleaning or repairs, but most importantly to prepare your buildings to be occupied again.

1 New England Journal of Medicine, Aerosol and Surface Stability of SARS-COV-2 as Compared with SARS-CoV-1.

Peters, P.E., MAC, CEICC, is a vice president with Rimkus Consulting Group an international forensic engineering company. He is a licensed Professional Engineer, Mold Assessment Consultant and Council-certified Environmental Infection Control Consultant with over 20 years’ experience designing and operating very large healthcare facilities and nearly 20 years as a forensic consultant.

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