What should we be considering as we exit Coronavirus (COVID-19) lockdown measures?

Coronavirus disease (COVID-19) pandemic will change the way we live and work for the foreseeable future; if not forever. We ask if you have taken the necessary precautions in your workplace or residence to reduce the risk of infection and transmission of harmful viruses once lockdown measures are relaxed?

The world today is so highly interconnected that a contagion such as the COVID-19 virus, first witnessed early in 2020, can spread rapidly.

Whilst the risk of fresh waves of pandemic exist, it will remain important that we change our ways of living and working appropriately to reduce this risk of transmission. The design and management of buildings and application of government guidelines will play a critical role in the success of this. In the short term, it is highly likely that more people will work remotely and that many spaces become transient. Importance of good design for such spaces is paramount to their successful usage.

At We Design For… alongside our partners, we are well positioned to advise on possible building and system improvements that will support and encourage healthy living and working, whatever the space.

What is COVID-19 and how do the particles behave?

COVID-19 is a new strain of Coronavirus virus, an infectious disease particularly harmful to human respiratory process and currently without a vaccination capable of reducing the impact on the world’s health services.

The coronavirus particle is 80-160 nanometres (1 micron = 1000 nanometres) and remains active in common indoor air conditions for up to three hours and on surfaces for up to 2-3 days. It is estimated that you require a dose of approximately 1000 particles  to become infected.

Humans can be exposed to pathogens via two mechanisms in the air; either by close contact transmission (by coming into contact with droplets exhaled from an infected person, larger droplets with a tendency to fall rapidly to surfaces); or the very low risk of airborne transmission (where aerosols/respiratory droplets (< 5 µm) can remain airborne for a number of hours if environmental conditions support such behaviour, otherwise evaporate (usually within milliseconds) and desiccate.

The size of droplets containing particles is particularly relevant to their behaviour in the air. Droplets of less than 5 microns tend to stay in the air longer than the more common droplets of greater than 10 microns that have a tendency to fall to surfaces rapidly . The smaller droplets contain fewer particles and as such are less likely to cause infection unless we are cumulatively exposed to large doses over time.

Authorities, including The World Health Organisation (WHO) and the NHS in the UK, are taking a pragmatic approach that airborne particles (aerosols) are viewed as low risk. However, there is very little scientific study of this available and whilst we know that aerosols associated with the respiratory process are rare, there is some evidence that they occur. We do know that human processes such as going to the toilet can also produce aerosols and would advise approaching this subject with due care until further scientific research is available.

Rethinking density and circulation…

Now more than ever, keeping to a recommended occupancy density in buildings is important.

To enable us to respect a 2m social distancing as per the guidance in the UK, occupancy density should not fall below 12.6m2/per person and should ideally be greater

To enable us to respect a 2m social distancing as per the guidance in the UK, occupancy density should not fall below 12.6m2/per person and should ideally be greater, rather than the 8-10m2/per person that is commonly adopted in the modern workplace.

However, it should be noted, that in many conditioned or ventilated spaces, such distancing rules of thumb may offer less protection against airborne particles. Temperature differentials (a consequence of heating spaces), ventilation and air conditioning systems, all encourage air movement in a space and an engineer should always be consulted when developing social distancing strategies in buildings to ensure that proposals are effective.

It should also noted and is recognised by the UK government that social distancing may not be possible in all situations. Where this is the case other measures such as testing, masks and screens should be considered.

Working hours and subsequent commuting patterns might also be reviewed. Staggering our commuting times could reduce pressure on public transport and avoid peaks for building entry. We could see IR readers gauging temperature and wellness of people at building entrances and hospital-style sanitation stations might be made available for use upon entry to buildings. 

Improved signage, wayfinding and demarcation in buildings may become more critical, communicating strategic messages to occupants, ensuring well considered circulation routes are adhered to and hygiene maintained.

The workplace…

At We Design For… we have supported working from home and remote working since our inception.

We see certain advantages to be gained from a flexible way of working, reduced travel times, the associated carbon footprints and benefits to the wider environment. If you live in a city, you only have to step outside during lockdown to notice the unquestionable benefits in terms of improved air quality, biodiversity and reductions in noise and pollution generally.

In a modern world, where virtual meetings are often more productive than those sat around a meeting table, we see the virtual environment being increasingly accepted as normal practice.

However, the advantages of collaboration, overhearing ideas in an office environment and face to face education and supervision of employees remain an item worthy of some debate. It has in the past been proven that putting people together does create value, but such principals are being significantly challenged by COVID-19, as businesses more widely realise that technology can still facilitate such positive behaviour.

COVID-19 is not simply impacting physical health, some of the psychological effects and how best to service employee’s mental health must also be considered by building managers, employers and designers.

COVID-19 is not simply impacting physical health, some of the psychological effects and how best to service employee’s mental health must also be considered by building managers, employers and designers.

Improvements to spaces may prove to be as valuable in terms of perceived benefit as they are of actual benefit.

Over recent years, when designing office space, We Design For.. have always looked to encourage flexibility in workspaces and improvements that will support occupant health. Whilst not always a possibility, ‘hot desk’ spaces that allow the occupants to move freely without being tied to a single desk and allowing lighting, power, data and comms, heating, ventilation and air conditioning systems to be cost efficiently adapted to change. Such opportunity for change may have added value at times like the current.

Intelligent Buildings…

Artificial Intelligence (AI) in buildings is very much a buzz phrase over recent years. At We Design For… we have always first asked if a system offers clear value for an end user, building owner or developer; ahead of recommending a complex control system.

However, there are many cases where there may be advantages of using such systems. As we continue to require some level of social distancing, it is highly likely that the majority of buildings will be subject to phased opening, and this may continue until there is a working vaccine to protect against the spread of the virus.

AI can be used to monitor occupant movement and notify building managers when and where occupancy densities are not being maintained within spaces or even where there is oppportunity for increasing density in under utilised spaces, flag potentially ill members of staff or visitors with airport style IR cameras capable of reading body temperature, spot trends in environmental conditions and as such enable HVAC systems to adjust to suit occupant preferences without their continued input and contact with controllers and convey messages supportive of building management.

Technology can support the majority of our desires, but we must consider the desires of every person to be subjected to such choices. Not every building occupant will be happy working in an environment where their movement is tracked and technology prevents them from going about their business freely. This should always be a consideration; productivity stems from health and happiness.

At We Design For.. we would not advocate anything that suggests a ‘big brother’ culture, as we are believers this will often have a negative impact on wellbeing.

Improvements to Heating, Ventilation and Air Conditioning…

As Building Services Engineer’s we are able to reduce the time that pathogens remain airborne within a space, by designing or improving the management of ventilation systems effectively.

Considerations that should be applied include the number and effectiveness of air changes in a space and the level of filtration that should be applied. Ventilation and air conditioning design may also be supplemented with the use of green infrastructure providing some additional benefit.

Whilst increased ventilation rates can provide benefits when exhausting air from a space, it is also very important that we consider the quality of the air we are bringing into a space, not simply with consideration of pathogens, but also other harmful particles and pollutants found in the air we breathe.

REHVA (The Federation of European Heating, Ventilation and Air Conditioning Associations) has produced interim guidance on the operation and usage of Building Services during the COVID-19 outbreak. This document was further summarised by Alex Smith, Editor of the Chartered Institute of Building Services Engineers (CIBSE) Journal, April 2020 and we have added our additional comment and recommendations based upon further reading on the matters discussed and our own opinion.

• Increase air supply and exhaust ventilation. The general advice is to supply as much outdoor air as possible, but this should consider the quality of that air to ensure that it is ‘fresh air’ and does not contain other contaminants harmful to human health and also the cost in terms of associated energy. Additional filtration will likely be required, particularly in a city environment. We feel that mask wearing and naturally ventilating a space where possible (See below) is probably a more effective and pragmatic solution to preventing transmission than boosting mechanical air flow, especially if the existing ventilation design is poor and may actually cause a greater spread of infection. However, some thought should also be applied to how mask wearing may influence productivity and human comfort?

• Where possible (Ie, outdoor air quality permits), increase levels of natural ventilation, open windows or implement natural ventilation strategies.

• Humidification has no practical effect. Whilst there is much conflicting information in the public domain, it appears that Covid-19 is resistant to environmental changes and is susceptible only to relative humidity (RH) and space temperatures outside of human comfort recommendations and as such not applicable in the built environment. However, humidification is suggested during winter months as nasal systems and the mucus membrane are more susceptible to infections at low relative humidity.

• Safe use of heat recovery is recommended. Heat exchangers that prevent leakage between the supply air side and exhaust air side are preferred. Summertime bypasses can be implemented where practical.

• Avoid use of recirculation where possible. For the same reason as heat recovery selection being key, recirculation should also be avoided. It is important that exhausted air is not recirculated back into a building. Where possible, fan coil units should be turned off as a means of protection. However, this is not always possible to maintain comfort levels. Where necessary appropriate filtration can provide some protection against larger droplets containing pathogens in recirculated air, but 100% fresh air systems are more effective at removal. We Design For… are well positioned to advise on the options available to you.

• Increases in the maintenance frequency of filter changes and ductwork cleaning will have little benefit. Increasing ventilation exhaust rates and avoiding recirculation is more important.

• Localised air filtration can be beneficial. This can come in the form of high end ‘air cleaners’ with high efficiency or HEPA rated filtration and appropriate airflow rates for the space they are sized for, or even the ‘active air‘ green wall systems that we have developed with Biotecture. Systems that come with UVGI filtration as an option to ensure air off these units is of a high quality.

• Ventilation design is critical. Consideration of airflow within and between spaces where pressure differentials exist is important. Where necessary CFD (Computational fluid dynamics) may be considered.

Materials and Operational Considerations…

FM teams will be faced with increased cleaning, new operational protocols and possible increases in waste products, however, their jobs can be made easier with flexible, clean desk policies and technologies implemented to support them.

We can be exposed indirectly to COVID-19 via contact with a contaminated surface or object.

Various studies have been carried out detailing the lifetime of COVID-19, and how the lifetime is affected by surface materials. This can vary from hours to days; with plastic and stainless steel, pathogens were still detected after 72 hours. Material choices in the workplace should begin to consider this data.

Soap and sanitiser dispensers, methods of surface disinfection, availability of tissues, self-closing rather than open bins, automated taps, self-closing toilet seats and the use of disposable towels, or hand dryers with a UV filtration function rather than conventional hand dryers, UV sterilisation methods generally (but with consideration of by products) and improved cleaning regimes, inclusive of general and personal equipment such as phones and laptops should all be considered.

If in any doubt, We Design For… and our partners, are very well positioned to provide services to support your transitional strategies in the built environment post lockdown.

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