The global Covid-19 pandemic has thrown the future of the open plan office into doubt. Social distancing measures and home working have undermined our culture of open workspaces, leaving many to wonder if those heady days will ever return.
Finding the balance between safety and productivity has become one of the most pressing concerns for businesses across the globe. As we prepare to fight the greatest global recession in history, and with a cure nowhere in sight, the stakes could not be higher. In this series of independent whitepapers, we ask leading industry experts to share their views on the key questions every employer is asking.
Professor Alan Hedge is Professor Emeritus in the Department of Design and Environmental Analysis, Cornell University. He directs the Human Factors and Ergonomics teaching and research programs. Prior to joining Cornell, he ran the Graduate Program in Applied Psychology and Ergonomics at Aston University, Birmingham, U.K.
In the first whitepaper in the series, Professor Hedge explores the science behind social distancing. We asked Professor Hedge for his views on what we as employers can do to minimise the risk of Covid-19 in the workplace whilst maximising the clear advantages of retaining as many open plan working practices as possible.
In this in-depth whitepaper, Professor Hedge explains his answers to the following questions:
- What will the final “social distance” dimension be in the workplace?
- How practical will social distancing be in the workplace?
- Can physical barriers negate the requirement to have social distancing?
- How will sit-stand desks impact on workstation layout?
- What will new cleaning protocols look like?
- What will access to and from workstations look like?
- How will one person push their chair back to stand whilst others remain seated?
- Using main access walkways
- Planning for post-Covid-19 when workstation density will increase once again
- Investment in new office furniture or re-organising existing product?
- Will the whole office furniture landscape change to be far more focused on strictly managed collaborative spaces?
What will be the final “social distance” dimension in the workplace? To understand the answer, we need to revisit our history…
Pandemic plagues have been a part of human civilization since recorded history began. But most of that time no one knew the course, but gradually suspicion built that it was “bad air” called the “miasma”.
In medieval times as international trade flourished, and especially sea trade, concerns about diseases being carried by seagoing vessels and that cargo started to grow.
In 1377 the port of Dubrovnik in Croatia introduced the first recorded ‘quarantine’. In 1423 the port of Venice built a quarantine (named from 40 days isolation) hospital on the small island of Santa Maria di Nazareth.
All goods being delivered had to undergo various kinds of cleaning and ship’s crew had to remain in quarantine.
Even though the course of a plague remained unknown for almost another 500 years, the act of physically and socially isolating an infected person was known to reduce the risk of disease transmission.
Fast forward to the 1890s when a German bacteriologist (Carl Georg Freidrich Wilhelm Flügge) identified speech droplets as a means of transmitting disease.
Back then there were no antibiotics, no vaccines, and no truly effective treatments against many respiratory infections, especially bacterial diseases like tuberculosis and viral diseases like measles.
In 1918 a major influenza, named the Spanish flu by the Americans (although the disease actually started in America!) ravage the planet, infecting one third of the world’s population and killing some 50,000,000 people.
Because of knowledge of Flügge droplets, wearing protective face masks capable of filtering droplets was found to be effective in reducing disease transmission.
Also, particularly in the USA, social distancing measures, including closing schools, shops, and restaurants, banning sharing cups, banning public spitting, placing restrictions on transportation, banning public gatherings and mandating social distancing, though no one knew what an appropriate distance should be.
In 1934 a professor Wells at Harvard University published a paper on how far droplets of different sizes would travel through air when they were dropped from a height of 1.8 m.
Larger droplets would quickly fall because of gravity. A fluid droplet in air evaporates and naturally get smaller over time, so the humidity of the air plays an important role and in humid climates less water evaporates from the droplet and it falls to the ground faster than if evaporation was occurring, because then the way to the droplet would be decreasing and it could remain airborne for longer.
What was found was that in still dry air, a droplet would travel horizontally around 1.7 m before hitting the ground, in normal air this would be 1.4 m, whereas a 90% humid air this would be just less than 1 m.
Wells assumed that after 2 m all droplets would have either fallen to the ground or completely evaporated.
Since that time there have been numerous studies that have investigated the effects of different speeds and in general have confirmed his findings.
So, in the current pandemic the WHO originally recommended a safe distance of 1 m, which was adopted by countries such as Denmark and China.
South Korea adopted 1.4 m, Australia adopted 1.5 m, the USA adopted 1.8 m (6’) and Canada adopted 2 m. The UK initially adopted 2m but then changed this to 1m+ on July 4, 2020 providing that the people are wearing some personal protective equipment (face masks, face shields etc.) or the environment has been modified to reduce droplet transmission (e.g. separation panels). So, there is no single distance for social distancing that is universally adopted.
These distances are appropriate if the air is still, but if the air is moving gently, as in an air-conditioned office, and the distances should be greater because the virus is carried on air currents.
However, if the air is moving very quickly then these distances can be less because the air will carry the virus away.
If people are wearing personal protective equipment, such as a facemask, a face shield, or some other protective equipment, then the social distance can be less as has been implemented in the UK.
If the air has been sterilised in some way, then the social distance can be less or if none of the people are infected social distancing is unnecessary.
How practical will social distancing be in the workplace?
Completely redesigning a building interior to accommodate social distancing is a short-term knee-jerk reaction to the current viral pandemic.
Redesigning a commercial office space to enforce a 2m social distance requires lowering the occupancy to less than 20% of workers. Doing this will be economically disastrous.
Apart from redesigning the office layout to accommodate social distancing, this may be almost impossible in other parts of the building, such as car doors, stairways, lifts etc.
Even if a company redesigns the space in this way, to date there is no evidence that uninfected employees will have no risk of viral infection in a building designed for social distancing, if an infected person comes into that space.
If a building is designed with individual private offices that each have operable windows the risk of any viral infection will be dramatically reduced, especially if each of these offices also has some sterilization technology, such as upper room germicidal ultraviolet lighting.
- If none of the employees in a building is infected with the virus, social distancing is unnecessary.
- If the air in the building is continuously being sterilised in some way, then social distancing is unnecessary.
- If employees have been vaccinated against the virus, once a vaccine becomes available, social distancing is unnecessary.
Can physical barriers negate the requirement to have social distancing (particularly about more static situations like around desks)?
If a physical barrier exists from floor-to-ceiling between an infected person and an uninfected person then, providing the ventilation system is not exchanging air between these 2 spaces without sterilising this air, there is no risk of infection being transmitted.
However, if there are air gaps around the barrier then it is possible for pathogens to be carried from an infected person to an uninfected person.
Placing a partial barrier that is approx. 1 m high in front of an individual will act as a cough/sneeze guard and catching the larger droplets can contain the virus.
But exhaled air is at 33C so the air naturally rises on a convective current which carries micro-droplets containing pathogens up and over the enclosure and into the breathing zone of any individual walking past that barrier and also into the general airstream of the office.
A similar effect happens if you place a rear barrier and 2 side barriers in front of an employee.
The situation is quite different if you place a ceiling cover on the 3 barriers so that this creates more of an enclosure that stops contaminants escaping above the barriers.
If you extend these barriers beyond the front edge of the desk to about the elbow distance of the individual, this creates a very effective “hood” over the person.
If you place a small air cleaner within the enclosure then that will minimise any exposure risk to the individual or to any adjacent employees and it will ensure that any air released into the general office space is free from airborne pathogens.
Here is an example of what such an enclosure looks like:
Remember! Office furniture that is easy to clean and made from materials that work as antimicrobial products is very important.
How does sit-stand working impact on workstation layout post COVID-19?
As it creates a more 3-dimensional aspect to the equation, someone sitting, opposite someone standing, means that any barrier must be much higher.
It is possible to place a partial enclosure, and preferably one with a ‘ceiling’ cover, onto a sit/stand desk so that whether the person is sitting or standing they are still being protected by that enclosure (see below).
If the enclosure has a ceiling to it and the person is sitting down, then that ceiling also will protect if somebody walking past coughs or sneezes.
What will the cleaning protocols look like?
Cleaning protocols are important in protecting against fomite transmission of the virus, i.e. surface to hands to face transmission.
It is important to keep objects that are frequently touched as clean as possible.
Studies show that dilute bleach wipes are very effective in deactivating the virus. UV-C lights are also very effective at deactivating the virus.
UV-C devices allow you to place small items like your cell phone or tablet and within 15 – 30 minutes the device will be sterilised.
You can buy antimicrobial devices, such as keyboards and computer mice, that are also washable.
Any surface material that contains copper, such as a brass handle, will work to deactivate the virus and is preferable to using materials such as stainless steel or plastic.
New surface treatments are being developed that will have antimicrobial effects that last for at least 7 days, so that daily cleaning becomes unnecessary.
Keeping floors clean will be important, so it is a good policy to either change your shoes on entering the building, as you would do if you were going to a gym, or wearing shoe covers at work, as you would do if you were visiting a hospital.
Some companies are using UV-C robots to roam the office space at nighttime to sterilise all surfaces.
These robots have very powerful lamps that will deactivate the virus in less than a second.
What will access to and from workstations look like?
Research shows that an infected person creates a cloud of viruses that extend in a plume. This extends up to 2.5m ahead of the person and up to 4m behind the person’s body.
If the infected person is moving faster, such as jogging or running, then the trailing plume can be even longer.
This means that ideally you should have a one-way port traffic route in the office and that you should encourage people not to walk too close to the person in front of them.
Preferably they should also walk to the side of that person to avoid being in their particle plume.
For stairways or corridors, where one-way traffic is not possible, then there should be a floor-to-ceiling barrier that separates the 2 sides of the corridor space or stairwell.
This will allow people to pass each other in the opposite direction without exchanging any exhaled air.
Use of lifts and social distancing in the workplace
The situation with lifts is complicated because it is an enclosed space. Here is what you can do to minimise the risk of contamination.
- Reducing the occupancy of a lift and putting markers where people should stand and how they should face is helpful.
- Installing air sterilisation systems, such as germicidal UV-C, will minimise the risks of exposure.
- Pressing lift buttons using the knuckle of a finger or preferably a pencil, pen or stylus, or having a touch free or voice activated lift also will be very helpful.
Is it a matter of training, or do walkways need to be widened?
Walkways do not need to open up dramatically if you can organize a one-way traffic system and if you can train people not to walk immediately behind and close to an individual in front of them.
Also, encouraging people to walk slowly will generate less of a plume of contaminants than walking fast or running.
Putting one-way arrows on the floor and entry or no entry signs can help re-educate people on how to move around the office.
How will one person push their chair back to stand whilst others remain seated and still more use the main access walkways?
If there is a system in place for ensuring that people entering the building are not infected with the virus then this should minimise the risks of anyone who pushes their chair back to stand while others remain seated.
If the desks are covered with the kind of enclosures shown above, then if a person raises their desk to standing level they will still be protected.
To be sure that a person going from sitting to standing does not contaminate surrounding air, if they are going to leave their desk, a policy of wearing PPE could be implemented.
Consider face-shields over facemasks as these also stop you from touching your eyes. There is some evidence that the virus can gain entry in this way.
Should we be thinking ahead and planning for the time when workstation density will be able to increase once again?
Yes, absolutely, I think we should be focusing on making changes to the current furniture workstations and the air conditioning systems in buildings rather than just making enormous changes to the current workspace layouts.
The changes outlined above will be effective in eliminating the virus from the airstream in a way that social distancing alone will not.
There is growing evidence of effective treatments for a COVID-19 infection that render this more like catching a cold than a potentially fatal disease.
Once a vaccine is generally available then simple social distancing measures will become even less important.
If, however, a company makes changes to their workstations and their ventilation systems as has been outlined, these changes will continue to protect employees against any future pandemic viruses or other airborne pathogens.
There is a discussion regarding investment in new furniture, rather than reorganising existing products.
Who will make the first move and invest at such an uncertain time?
Running the risk of getting it wrong or making a large financial outlay on something that becomes obsolete very quickly?
I believe that investing in either modifications to existing furniture, such as retrofitting personal enclosures and providing personal air cleaners within those enclosures, or installing new furniture that incorporates the same capabilities, will be a far better use of resources than reorganising the office workspace completely.
Providing that what companies install is based on sound scientific principles then there is no risk of “getting it wrong” or of that furniture becoming obsolete very quickly.
Will the whole office furniture landscape change to be far more focused on strictly managed collaborative spaces?
Completely open plan offices as we know them are dead!
The landscape office, which in the USA became more like a cubicle farm, offers more protection against airborne pathogens. Something along these lines may be the shape of future offices.
However, the ideal office space will be one in which each employee has the equivalent of an individual office with a closable door and either an operable window or an air cleaner within that space.
This is the kind of arrangement that one might find in a university or a government building.
As video-chat technology continues to improve this will replace the need for conventional conference rooms and there will be less and less need for any face-to-face collaborative meetings, at least until there is an effective vaccine against the virus.
Video chat technology can dramatically speed the flow of information by eliminating travel times and by facilitating just in time almost spontaneous meetings.
Other spaces where people might congregate such as cafeterias or libraries similarly can be replaced in other ways.
Most library resources are available electronically these days. Food services that deliver meal choices to a person’s desk at work may return to fashion rather than individuals going to large cafeterias.
In some Asian countries cafeterias also are being retrofitted with transparent physical barriers between eaters so that there is minimal risk of transmission of the virus or any other airborne pathogens.
Do you have questions about reorganising your workspace to accommodate greater social distancing? Adapt Global is one of the world’s leading ergonomic workplace furniture designers.