You can’t manage indoor air quality without measuring it first

Lots of people are selling products that are supposed to improve indoor air quality. They may be air purifiers, filter systems, complex green walls or even pot plants. Many claims are made, but how do you know whether the systems you are buying are doing what you need them to do? This is where air quality monitoring comes into its own.

(By the way – I’m not trying to sell you an indoor air quality monitor, or any form of air purifier. However, I can help your business set up an IAQ monitoring project and even help you on your way to gaining a RESET certification for your buildings, which will also help you with WELL and Fitwel certifications – please get in touch if you want to know more).

Why monitor indoor air quality?

Good indoor air quality is often thought of subjectively.  Human perception of good air quality is difficult as our senses evolved to deal with environments that were unpolluted.  As long as we could detect smoke, which suggested an immediate threat (or, conversely, the possibility of a cooked meal and convivial company), air quality was not much of a concern to our plains-dwelling ancestors.

Inside buildings, we often only notice an issue with air quality when it directly affects our comfort. We might describe the air as heavy, fusty, stale or stuffy. Stuffiness (often as a result of elevated carbon dioxide from our exhalation, combined with warm temperatures and high humidity) can be alleviated by opening a window. Carbon dioxide (and airborne viruses, such as Covid-19) inside the building is diluted by bringing outside air in, and humidity and temperature might also be made more comfortable.  This improvement to our comfort, achieved by a perceived improvement to indoor air quality, is not the whole story.

Opening the windows might risk exposure to other harms that are not readily detected by human senses.  Fine particulates, volatile organic compounds or various oxides of nitrogen or sulphur are not usually detectable by human senses, so how do we know whether they are present?

Only by using calibrated IAQ monitors that measure, record and report key parameters of air quality can you then set out to manage air quality and reassure the users of the building that their safety and comfort is being looked after.

Without data from air monitoring, any management of indoor air quality is pretty-much based on guesswork, which is inadequate for the proper management of risk in a building.

My new white paper explains how and why organizations should develop an indoor air quality monitoring and management programme, which you can download here.

Interior landscapers! I can help you write marketing copy that is based on evidence, science and research to make your messages more credible

Earlier this morning, I encountered a post on LinkedIn that made me a little cross. It was a post about the benefits of moss walls.

I like moss walls. They are a great way to add greenery to a space where live plants can’t thrive and they can be made into the most fabulous designs. Indeed the moss wall illustrated in the post was fantastic. The poster then started to make some claims. They started out OK, and if the author had stopped at a certain point, then everything would have been fine: a great moss wall, well illustrated, and a fantastic addition to any space.

Unfortunately, the poster then managed to conflate some research that he might have read about the impact that live moss has on improving air quality. I’ve read some of that research and it seems pretty sound to me, and I have been watching the development of live moss walls with interest – this product, for example, looks amazing.

However, it wasn’t a live moss wall that was being shown, it was a preserved moss wall. This is actually made with preserved lichens – a different type of organism altogether – and something that, when preserved and stuck to a wooden board, would stretch the definition of ‘alive’ to breaking point.

A little bit of sense checking with a technical person would have prevented this mistake and could have allowed the post author to create an article that wasn’t spoiled by a claim that is easily challenged.

It frustrates me when the marketing of good products and services is spoiled by over-exaggerated claims. It annoys me when marketing people put down people with technical knowledge because they have the temerity to point out that a claim might not be terribly robust or might be open to criticism. It really struck home once when a marketing team I was working with were desperately trying to put together a set of questions for a survey. In my naivety, I assumed that they were seeking objective data upon which to build a campaign and a message based on those data. This wasn’t the case. The exercise was to collect survey responses that would appear to validate the claims that they had already decided to make, and they were trying work out how to frame the questions to generate the answers they wanted to back up the claim. I was told that I needed to think like a marketer – was that an admission that marketing isn’t necessarily about truth?

Over the last several years, I have written articles and blog posts to support the marketing efforts of employers and clients. I think that I’m reasonably good at it. The reason that I think I’m quite good at it is because I write about what I know, have researched and am confident is true. Objectivity and reliance on evidence are crucial. I champion evidence-based design, solutions and propositions.

If you are an interior landscaper or in a related industry, and would like me to help you write marketing copy that is backed by evidence, science, research and over a quarter century of technical expertise in the industry, then please get in touch.

E-mail or telephone +44 (0) 7543 500729

Can indoor plants really improve indoor air quality?

A lot of indoor plant sellers will tell you that indoor plants will purify the air. Sometimes, they refer to experiments carried out by NASA to prove the point.  However, careful analysis of some of these claims shows that the claims are often exaggerated, or taken out of context.

That doesn’t mean that plants have no impact on indoor air quality – they can.  So, how can you get the most of plants’ abilities to affect the indoor environment? I can’t promise miracles, however.

A brief history

In the early 1980s, NASA was investigating the ways that astronauts could maintain their environments whilst on long-term missions.  The reaction of photosynthesis is a way of producing fresh oxygen for the astronauts to breathe, and some plants are good at removing other pollutants from the air and water.

The idea was that by having completely sealed living environments, coupled with optimal growing conditions for vast amounts of greenery, humans and plants could live in complete balance and the resources needed for a long-term mission could be reduced.  At the time, only a few years after the last manned landing on the moon and with early space stations (Skylab and Mir – the forerunners of the International Space Station) being lived in for months at a time, this research was clearly very important.

The results of the experiments showed that some plants were especially good at removing pollutants such as some volatile organic compounds (VOCs), some of which are quite unpleasant and are associated with harmful indoor air quality.  These have become quite well known and are often referred to as the NASA list of air cleaning plants.

Sick buildings – could plants be the answer?

In 1984, the World Health Organization gave a name to a recently discovered phenomenon.  People were feeling ill in modern buildings, and analysis of the environments in some of these buildings identified a number of VOCs as being likely causes of the problem.  That problem became known as Sick Building Syndrome, and a great deal of effort was expended trying to identify the building components most responsible for the release of these chemicals into the air inside buildings.

It didn’t take long for someone to notice that a lot of the VOCs identified as being associated with sick building syndrome were those that some plants seemed to be good at removing.  Indeed, one of the scientists involved with the original NASA experiments – Bill Wolverton – has since made a career writing about how houseplants can create fresh air.


Thinking back to the original NASA experiments, you will notice that they were carried out with a specific purpose in mind, and the plants were grown under conditions that made them actively grow – their metabolism was optimized by controlling the environment with high light levels, good humidity, warm temperatures and precise levels of plant nutrients.  There were also vast numbers of plants in the growth chambers.

If you ever visit the hot houses at a botanic garden, such as Kew or the Eden Project, you will experience exactly the type of environment the plants experienced in the NASA experiments.  The air inside those spaces is uplifting, fresh and life-supporting.  The difficulty lies in recreating those conditions in homes and offices.

Issues of indoor air quality

Fortunately, since the early 1980s, the use of products in buildings associated with sick building syndrome has been significantly reduced.  Most homes and offices are not full of nasty VOCs.  However, there are some pollutants that have the potential to cause harm, or at least discomfort. 

Volatile organic compounds (VOCs)

There are many sources of VOCs in houses. In fact, almost everything you can smell is a VOC of one type or another. Paints and new furnishings often release some compounds, but more mundane products are the biggest source: cleaning products, cosmetics and toiletries. Cooking, too, also produces types of VOC, as does opening a bottle of wine or mixing a cocktail. Most of these VOCs are harmless, although some can be irritating.  Other VOCs are actually the result of human physiology: when you breathe out, there will be some VOCs on your breath as well as carbon dioxide and water – these are just the products of digestion and metabolism.

More worryingly are the VOCs that can enter the house from outside. Vehicle emissions, agricultural and industrial activities all contribute to VOCs in the atmosphere that will find their way indoors.

Fine particulates

A more pernicious threat to human health comes from ultra-fine particulate matter, usually produced as a result of combustion.  These are often classified as PM10 (particles smaller than 10 μm in diameter) and PM2.5 (particles smaller than 2.5 μm in diameter).  These particles can be breathed deeply into the respiratory system, where they remain.  Fine particulates come from vehicle exhausts, inefficient combustion of gases and even cooking.


Larger particulates, such as dust, can irritate the respiratory system and contribute to asthma and allergies.  These are either produced inside buildings (and are usually composed of dead skin cells and pet dander), or can be blown indoors through doors and windows (such as fine dust from roads and fields or construction, or pollen from trees and grass).  Since most homes are not airtight (and most people wouldn’t want them to be – opening a window is a great way to refresh the air and create cooling breezes indoors), there is little that can be done to prevent dust from getting in from the outdoors.  Remember, also, that good ventilation is recommended as a way of reducing the risk of Covid.

Carbon dioxide

Elevated levels of carbon dioxide are more of a problem in offices than in homes. Small meeting rooms with lots of people, will result in CO2 levels rising fast and getting to concentrations high enough to cause drowsiness and impair cognitive function.  In the home, this is less of a problem, although in the winter, when everyone is indoors and windows remain firmly shut, CO2 levels might rise above comfortable levels.

How can plants help

Despite the fact that most homes are unable to house enough houseplants to actively purify the air, nor are they able to provide the conditions for them to be physiologically active enough to achieve the sorts of effects seen under laboratory conditions (that would be extremely uncomfortable for people), there are ways that plants can be used indoors to improve air quality – and some plants are better than others.  

The key is to match the plants well to their environment.  The more closely matched they are, the more physiologically active they will be, and that is when the effects will be greatest.

When you search for indoor plants online (whether for home or office), you will often see that retailers often include details about the conditions that they do best under.  If you choose plants that suit the different conditions found in the various spaces in your home or office, then you are more likely to notice an effect.

Plants affect the indoor environment in three main ways.

First, the bacteria in the soil that live amongst the roots are able to break down some VOCs, and convert them into substances useful to the plants.  This is an entirely natural phenomenon, although only relatively recently properly understood in horticulture.  Plants with healthy roots and good soil will have the biggest impact, and those that are the fastest growing will also be the most effective.

Second, plants that are actively photosynthesizing will be removing some carbon dioxide from the air. Plants that originate in dark tropical conditions (such as rainforest floors) are able to photosynthesize extremely efficiently – they have evolved ways of making photosynthesis work even in very low light conditions, so that means more carbon dioxide is used by the plants.

Third, plants with hairy or slightly sticky leaves are able to trap particulates on the leaf surfaces, including fine particulates.  In fact, plants such as ivy and Cotoneaster are used outdoors to mitigate the effects of pollution in urban areas.  Some indoor plants can do that too (although they will need to be cleaned – there is no rain indoors to wash that pollution away).  In fact, research carried out at Washington State University some years back showed that many different types of foliage plant attracted dust to their leaf surfaces – possibly as a result of an electrostatic effect – so almost any leafy plant will be useful.

Which plants work best

Plants that are adapted to low light conditions will be the best to improve indoor air quality, especially reducing VOCs and carbon dioxide.  Plants in the aroid family, such as Spathiphyllum, Philodendron species, Aglaonema species or Monstera species will be good, as will other jungle-floor plants such as Calathea species, Ctenanthe and even small palms, such as Dypsis lutescens.

If light levels are slightly higher, Dracaena species have been shown to be effective at reducing levels of carbon dioxide (experiments carried out in Australia by Margaret Burchett, Fraser Torpy and colleagues, in real office conditions have shown that relatively few plants are needed to have a measurable effect).

Plants such as Ficus benjamina and varieties of ivy (Hedera helix) and some ferns that do well indoors are good at removing particulates.

Technological solutions

Over recent years, the plant/microbe interactions in the soil have led to a number of innovations that use plants to actively clean the air.  These systems were originally designed for large commercial spaces, but domestic-scale systems are becoming available.

In commercial buildings, green walls can have a dramatic effect on indoor air quality – especially when set up with good lighting systems. 

In the home, small green walls can now be purchased for relatively low cost, and can be installed by a competent DIYer.  Not only do they take up little in the way of floor space, the large volume of compact plants in a good root environment means that they are going to be very effective – especially if you invest in some plant lights to illuminate them (and these are also getting much cheaper).

More recently, active air systems have been developed that use fans to pass air through the foliage and the roots to increase the size of the effect.  Domestic-scale active air green walls are being developed and table-top systems, such as Vitesy’s Natede planter, are now already on the market.

disclosure note: the author has commercial relationships with foli8 and Vitesy

Indoor plants for a quiet life

I recently came across an interesting video, via a post on LinkedIn, on YouTube that explained, with the aid of Nerf guns of all things, how room acoustics could be modified by using different shaped acoustic panels.

The explanation is simple and very elegantly delivered. It also reminded me of some research carried out in the mid 1990s by Dr Peter Costa at Southbank University in London. His research looked at how interior plants can be effective at modifying room acoustics and make loud places quieter.

Noise, especially in offices, can be very distracting and can even cause stress. Mental discomfort, as well as being distracted from the task at hand, can make work unnecessarily tiresome and unproductive.

As people start heading back to the office, they may rediscover the nuisance of noise that might have been missing when working at home. Most homes are actually quite quiet (apart from the noises of children, domestic appliances and pets), and this is because of the amount of soft furnishings, fabrics and carpets that are commonly found.

The office, however, is different. Large, open plan spaces with hard surfaces and lots of right angles can be very noisy places. Sound is reflected all over the place and often not well absorbed. Sometimes you can find yourself tuning into a conversation from several desks away just because you happen to be in the path of the sound that is being bounced around the place.

There are very many excellent manufactured acoustic products that can minimize the effects of distracting noise in such places, ranging from fantastically sophisticated computer-controlled sound masking systems, using arrays of microphones and speakers, to simpler (yet still highly effective) products such as acoustic panels that can be placed in just the right places to deaden the noise.

Noise reducing vegetation

Looking again at the video, the key point is that by introducing shapes that disrupt the path of soundwaves as well as absorbing them, is a very effective way of reducing noise. This is where plants can make a useful (and very cost-effective) impact.

Plants are very irregular in shape. Their leaves point in different directions, are often textured, and foliage comes in all sorts of shapes and sizes. Mix up a variety of plant types and you will have surfaces scattering soundwaves all over the place.

Plants reduce noise by either absorbing sound or by breaking up the sound and scattering it through diffraction and reflection.


Plants alter room acoustics by reducing the reverberation time. Plants work better in acoustically live spaces, such as those that have hard surfaces like marble walls, exposed concrete and stone floors.

Diffraction and reflection

At lower frequencies plants may diffract and reflect sound. This is because the leaf size is small by comparison to the noise wavelength. Plants with lots of small leaves are useful as they scatter and diffuse sound. At higher frequencies the leaves may reflect sound towards other surfaces that may then absorb the noise.

By placing plants around a space where noise reflections are most likely to cause problems, you can achieve some meaningful improvements.

Green walls and moss walls have especially good acoustic properties. Green walls, as well as having a mass of dense foliage, are often mounted on panels made from products such as rockwool or dense foam plastics, both of which have excellent sound absorbing properties in their own right.

Green wall in the UK, designed by the author and installed by SH Goss and Co. Ltd

Moss walls are an excellent choice where a live plant green wall is not practical. The shape of moss deflects sound, whilst the texture of soft moss absorbs sound. Mounting materials also have some acoustic properties and, as they cover a large surface area, they absorb sound at different heights and from all directions.

Moss wall by Metiez Moss, Netherlands

As discussed earlier, noise levels in a large space are often not uniform. There are multiple noise sources, and the sound from any particular noise source can be magnified or focused some way from its origin due to the layout of the space. Sound might be reflected in one direction and blocked from going elsewhere. A distracting noise might be perceived some distance from its source. Sometimes the only way to be sure of where noise is coming from is to take some objective measurements with a noise meter and map where the noise ‘hotspots’ are found.

Measure the noise levels all around space, ideally when noise levels are typical for the location (e.g. during normal working hours for offices). You can create a map of the noise levels on a floor plan of the space by noting where noise levels are especially high or low. Then, try and identify the sources of the noise as well as where the noise is loudest (as discussed earlier – that isn’t necessarily the same place.

schematic of an open plan office floor plan
schematic of an open plan office with noise hotspots mapped

Noise meters are relatively inexpensive, and there are some quite useful apps for smartphones too that can be quite accurate (and are certainly capable enough to be able to measure relative differences in noise from place to place).

Once you have a map of noise levels and sound sources, then you can think about where vegetation will have its greatest impact.

Green multi-taskers

As well as being excellent noise management tools, don’t forget that plants in buildings have a multitude of other benefits, not least their ability to improve wellbeing (and workplace effectiveness) when used as part of biophilic design.

For more information about how plants can make buildings better places to be, please get in touch. I can help building managers with your properties, or interior designers and interior landscapers seeking to add evidence-based value to your designs.

I am now a RESET Accredited Professional: what does that mean?

A few weeks ago, I completed my training and passed an exam to become a RESET Accredited Professional (AP) – one of approximately 500 around the world, and one of 51 offering services in the UK.

RESET is a data standard relating to the monitoring, recording and communication of indoor air quality. By being an accredited professional, I can now advise organizations and help them deploy an IAQ monitoring and reporting set-up that provides credible and independently-verifiable data on several key IAQ parameters, which can then be used to inform decisions on what IAQ solutions to deploy.

All too often, IAQ products and services are offered without sufficient evidence to demonstrate efficacy, or even need. Sometimes, some quite outlandish claims are made and impressive statistics are quoted that might be completely irrelevant to the context of the space concerned (interior landscapers – I’m looking at you. You can’t keep banging on about so-called NASA research on using plants to improve air quality if you don’t know how to measure it).

If you don’t know where to place an air monitor, how to interpret its data or even whether the monitor is accurate, then how can you be sure that your interventions to improve air quality are working? This is where a data standard is really useful.

The RESET approach is not a design standard – it doesn’t tell you what you must put in your buildings to improve air quality. RESET is a data standard. This means that if your organization is RESET certified, then you (and the users of your building) can be sure that the monitors you use measure the key IAQ parameters correctly (carbon dioxide, VOCs, temperature, humidity and fine particulates), and that the data provided by those monitors is handled, recorded and reported securely and impartially.

RESET also requires that IAQ data is made available in real time to the end users of the building (not just the building manager). This empowers users (e.g. office workers) to hold employers to account for the health and safety of their environment and can even help people make their own decisions about adjusting the environment to be more comfortable and healthy.

For me, being a RESET AP allows me to offer genuinely evidence-based solutions to my clients. I know how to set up an IAQ monitoring system, and I can then apply my knowledge of indoor air quality to recommend the most appropriate solutions (or point my customers in the direction of someone who knows better than me).

RESET is aligned with WELL, Fitwel and the Living Building Challenge, so if you are pursuing one of those standards, having a RESET-certified project will allow you achieve the relevant prerequisites relating to IAQ monitoring and reporting.

Another indoor air quality conundrum

Yesterday, the UK government announced that all remaining restrictions relating to Covid-19 are to be relaxed on July 19th. There will no longer be a requirement to work from home when possible (something that seems to have been gradually ignored by many organizations for weeks already) and schools can abandon bubbles and even mask wearing and social distancing.

To mitigate some of the effects of increasing infections and the removal of passive measures such as masks and distancing, better ventilation of buildings is encouraged.

One way to measure ventilation is by using a proxy measure of carbon dioxide concentration, and that is pretty easily achieved with IAQ monitors. Carbon dioxide concentration is a good proxy measurement for ventilation as the higher the levels of CO2, the fewer air changes are taking place. If CO2 levels are high, then increasing ventilation is a good option. Not only will it have an impact on virus transmission, but it will also improve cognitive ability and reduce the risk of drowsiness. High levels of CO2 are very much associated with poor productivity.

Awair Omni OAQ monitor

The easiest way to improve ventilation is to open some doors and windows. In most schools, that is the only way to do it – very few schools have complex HVAC systems that can adjust ventilation rates and still pass air through filters.

If you have an IAQ monitor that measures a range of parameters, such as particulates and VOCs as well as CO2, then as soon as you open a window, you might discover that other pollutants increase rapidly – and then what are you going to do? Balancing the health risks of the different contributors to poor IAQ is hard enough already, without the added complications of a nasty virus

Many schools, especially those in urban areas, as well as office buildings, are situated near busy roads and particulate pollution especially is known to be very damaging to respiratory health. Measurements of particulates near roads are sometimes way above safe limits and high concentrations of fine particulates can kill or seriously damage health.

Photo by thevibrantmachine on

So, here is the puzzle that has to be solved. Will opening windows to reduce the risk of ill health due to airborne viruses (such as Covid-19) cause a bigger impact on health by letting in a whole load of other pollutants, especially fine particulates?

There are, of course, some things that can be done to reduce the amount of particulates getting into buildings.

The first is to reduce them at source. In urban areas, the main source is traffic, especially traffic using internal combustion engines. The rapid increase in electric vehicles is certainly going to help, but it will take many years before they are off the roads completely, and the most polluting types of vehicle are the hardest, at the moment, to electrify (big goods vehicles).

Next, you can try and reduce the chances of those particulates getting inside a building with open windows. This is not going to be easy, but there are some effective measures, and they are mostly green.

Green walls, green screens, climbing and scrambling vegetation, trees and hedges are all capable of trapping large quantities of particulates on their foliage, and have an impact on urban heat islands too.

A Mobilane Ivy screen trapping particulates and keeping the noise down

Trees, hedges and plants like ivy are actually quite cheap too, and they are self repairing. They also reduce noise and look good too.

In the short term, using ventilation to flush out viruses (along with excess CO2) is going to be better than leaving windows closed and minimizing the ingress of fine particulates, but that is not a viable long term solution. Ideally, we should always have good ventilation to flush out viruses (it would be a good idea to use ventilation against all respiratory viruses, not just Covid-19), but if that is the case, we must do more to prevent other pollutants getting inside buildings. Vegetation is going to help a lot, but removing the source of those pollutants has to be the ultimate goal.

An indoor air quality conundrum

Something smells good

I have seen a notable increase in the number of posts on platforms such as LinkedIn extolling the benefits of ambient scenting – the addition of a high quality fragrance to the air inside buildings to make them more appealing (this is not the same as the use of air fresheners, no matter how sophisticated, to mask malodours in settings such as washrooms).

This is actually a subject I know quite a lot about (I’ve had a bit of a love/hate relationship with the subject since about 2007), and I can certainly vouch for the effects that scenting has on mood and the perception of the qualities of a space.

Ambient scenting can be used to reinforce brand values, make a place appear more luxurious and has even been shown in some experiments to reduce anxiety in healthcare settings. Some smells are very good at increasing the perception of good air quality – think of those fragrances that smell especially clean, fresh and hygienic.

Ambient scenting also has a role to play in biophilic design – potentially a very big role. Our sense of smell is our most primitive and we often react to a smell before we are consciously aware of it. Scents redolent of nature, when combined with appropriate visual and textural stimuli certainly add an extra dimension to a space – when our senses are stimulated congruently, our surroundings make more sense to us.

The technology of scenting is highly sophisticated (far more complex than an aerosol can or a scented candle) and is often programmable and even web-connected. Furthermore, the actual amount of fragrance chemicals released into the environment is actually really tiny – just enough to be perceived (this is especially true of nebulising systems). Some systems are designed to scent whole buildings through the HVAC infrastructure, with the fragrance oils introduced directly into the air handling unit.

Cleaner air

As well as spotting the increase in the number of posts about the benefits of scenting, I have also seen an increase in posts about air purifiers. This is clearly a hot topic. Even before the Covid-19 pandemic, poor air quality was high on the agendas of public health officials and building managers. Poor indoor air quality is associated with symptoms related to sick building syndrome and can, at times, pose a risk to the health of building occupants.

The development of new building standards, such as RESET, and the incorporation of IAQ monitoring standards into schemes such as WELL has brought not only management of IAQ, but also the monitoring and reporting of IAQ to the fore.

This is a good thing, and a subject that I have touched upon before. New research has shown that an increasing number of people are expecting more transparent reporting of IAQ in offices, especially amongst those facing a return to regular office work as pandemic restrictions ease.

Air purifiers are interesting products as well. Different systems employ a variety of technologies to remove fine particulates and remove, or breakdown, volatile organic compounds (VOCs).

Unfortunately, as far as I know, none of these air purifiers is able to distinguish between harmful, or unwanted, VOCs and those that smell nice and which were put in the environment deliberately.

The conundrum

The issue that is puzzling me is that many of the companies promoting ambient scenting are also promoting air purifiers, and this strikes me as strange. What drives this corporate cognitive dissonance?

If a company is selling an air purification system, one would hope that their sales people are able to present the features and benefits with some degree of conviction and be able to explain how an air purifier works and what it does to the chemicals circulating in the air.

Likewise, a sales person selling a scenting service should be able to explain how adding more chemicals to the environment can improve the users’ experience of a building (a scenting machine is a product that is designed to actively put more chemicals – no matter how safe they might be – into the environment). I’m not trying to be confrontational here – buildings that smell nice can certainly make using that space more enjoyable. People use fragrances all the time in homes and, of course, on their bodies.

It is quite possible that in situations like these it is likely that the left hand is unaware of what the right hand is doing. The people selling air purifiers may not be the same people that are selling ambient scenting (even if they work for the same company).

Furthermore, the purchaser of the scenting system might not be the same person as the purchaser of an air purifier (even if they work the same customer). If it is the same purchaser, that person now has the burden of potentially making an uninformed choice: is it reasonable to expect a customer to know that the air purifier will eliminate, or at least reduce, the efficacy of their expensive ambient scenting system?

One mitigating argument is that scenting systems are supposed to be situated where air purifiers aren’t. If that principle was universally applied, then there might be no issue – and maybe that is the norm. But I am not convinced that is always the case, especially with an increase in sales of portable air purifiers. These, by their nature, are going to be moved around and quite possibly moved into spaces where there is a scenting system in place. It is also possible that the person specifying the air purifier is unaware of the the presence of the scenting system.


I think it is unlikely that companies are deliberately selling both services to be used in the same spaces. There might be a short-term gain by doing so – the customer is going to get through a lot more expensive fragrance than might otherwise have been the case – but I doubt it would take very long for them to spot the problem.

Being a benevolent sort of person, I suspect that the poor sales people flogging air purifiers and scenting systems might not be sufficiently aware of the other products and services offered by different parts of their company (although their marketing departments ought to be). And if they are unaware, it makes it harder for them to help their customers make informed choices. This is clearly an opportunity for some training to be given (and if you are one of those companies facing this dilemma and would like some training developed for your sales and/or marketing people on this matter – please get in touch and I might be able to help you).

If sales people are actually selling both types of product, especially to a purchaser that might be responsible for buying both types of product, then there is an even greater need for some education to ensure that they remain credible and really understand the needs of the customer.

Biophilic design in the new workplace

I had the great pleasure of being interviewed by Dr Vanessa Champion, editor of the Journal of Biophilic Design last week. We discussed biophilic design in the new workplace and also biophilic design in the home working environment (which is, for many, going to be the workplace for a significant portion of the working week).

Personalisation of space is a key message in this podcast. There are tips on how Biophilic Design supports and benefits the whole person and how it enhances a whole sensory environment. Some designers might separate off those elements from Biophilic Design, but they are all an integral part, including views, improved acoustics, lighting, ergonomics and when used together provides us with an holistic solution. It’s all about comfort.

As a horticulturalist, I also discuss the benefits of plants, and we also talk about new styles of workplace and ways of working. People are talking about new hybrid ways of working, where some are working from home, some are in the office, and some half and half. Creating collaborative spaces, being able to break up big expanses of open plan offices with planting is an excellent idea. It also will give the feeling of comfort, improved acoustics, privacy.

Biophilic design and animal products

Recently, someone asked me whether I thought leather had a place in biophilic designs. It’s an interesting question, which I answered with a few off the cuff ideas, with the promise to think about it in more detail.

My initial response to the question is “it depends”. As someone that eats animals, and has no religious belief, I have no ethical problem with using animal skins and animal fibres, as long as it is not gratuitous or involves endangered wild species. I wear leather shoes, and have, in the past had leather sofas and leather upholstery in a car.

Everyone’s ethics have their boundaries, though, and there may be no logical reason for those limits. For example, I’m not a fan of fur farming (but what is the real moral difference between eating and wearing an animal?), and I am certainly very interested in seeing how lab-grown meat develops.

As mentioned above, I have no religious beliefs, but many do. The ethics of the religious are guided by the teachings of their religion, and there may be taboos about which animals may, or may not, be exploited for food, fibre or hides.

It could be argued that leather is a good use of a waste product. If we, as a society, are content with farming animals, then surely it is right that we use as much of that animal as possible. That might make leather a useful (and arguably a more sustainable) product, but not necessarily biophilic.

Moving back to the main question: does leather have a place in biophilic designs, assuming no ethical objection? From my own, possibly narrow, perspective, I’m not sure that leather is, per se, a biophilic material, even if it is a natural(ish) product. It is highly processed – rarely resembling an animal skin by the time it is tanned, coloured, stretched and made into a product.

For me, biophilic design is first and foremost about comfort – physical and psychological. We are most comfortable when we are in environments that stimulate our senses in a way that reflects our evolutionary history as plains-dwelling animals, using well-adapted and highly evolved senses to find food, fuel, water and shelter. This is something I have covered in previous posts, so won’t go into great depth here.

This might be a biophilic space, but does the sofa have to be leather to make it so?
Photo by Ksenia Chernaya on

In artificial environments, like cities, we can recreate concordant sensory stimuli through design, and that might (and often does) mean the use of artificial materials. In fact, in urban environments, it is only possible to create biophilic environments by using a wide range of synthetic materials and manufactured products.

Floor coverings are an excellent example of where synthetic products can be used in a biophilic design (good examples from Interface, who are pioneers in biophilic design and sustainability), and wall coverings too. Consider also lighting and acoustics. Modern biodynamic lighting and AI-generated soundscapes that recreate natural stimuli are only possible with advanced technology.

One final point. Good designers make sure that they are aware of the users of the environments they design. In commercial spaces, it is likely that vegans, or followers of some religions, will find the use of some animal skins or animal fibres offensive or taboo. In that case, why risk unnecessary hurt when there are alternative materials available.

So, in conclusion – I think that it is possible to create fantastic biophilic spaces without using leather or other animal products. On the other hand, if a designer (and all the users of the space that designer is creating) have no ethical issues with using animal products in design, then they can be used as part of a biophilic design.

Post pandemic plantscaping. Part 2

What’s next for the interior landscaper?

The interior landscaping industry is having to adapt very quickly to changing market conditions, and it has been fascinating to watch how that is happening.

After the initial shocks of Lockdown 1, followed by the gradual reopening of offices and hospitality over the summer, many in the industry looked to adapting conventional ways of doing business to adapt to the physical changes in the workplace. A lot of effort was put into using vegetation to enable or encourage physical distancing – screens, barrier planters, plants used to enforce pedestrian traffic flow around a building, etc. These all had some short-term impact and kept many interior landscapers busy (and in business).

Clean Team Florence sanitizer planter from Livingreen Design

Others looked to diversify their offering. Innovative planter manufacturer, Livingreen Design, developed a range of planters that incorporate a hand sanitizer dispenser, which, along with other hygiene and disinfection services has allowed some plant companies to offer additional valuable services to their clients – although keeping plants extra clean is also a challenge.

It’s going to be relatively easy to wipe down desks and screens once or twice a day with a disinfectant wipe, but we don’t know how well, or for how long, viruses can survive on the surfaces of leaves, flowers or moss. We also don’t know the effects of using surface disinfectants or fogging on plants: many plants are not going to thrive with a daily dose of Dettol spray. With those considerations, it may be that companies decide that plants in offices are going to be too much trouble.

Great for desks and hard surfaces, but what about plants?

Lockdowns 2, 3 and beyond: What can plantscapers do?

Hoping that everything is going to return to the way they were, and planning on carrying on as before, is probably not going to work. The landscape of the workplace (as well as hospitality and retail) is going to be very different – for months, if not years to come. How can the interior landscaping industry adapt?

Doing nothing and hoping for a return to the pre-Covid ways of doing things is likely to lead to bankruptcy. Even with the promise of a vaccine being realised, too many businesses have noticed the benefits of home working and other hybrid set ups. Office costs will be lower, and office buildings will be reimagined. Employees will see many benefits from more home working (time and money saved on commuting, being one advantage) and the towns and suburbs might be revitalized as city centre business districts get quieter.

That means conventional interior landscaping will be less appropriate than it was before. Offices that do remain are likely to resemble co-working spaces and have more in common with hospitality venues than conventional open-plan offices.

Indeed, the trend to such design styles was made evident recently when Plants At Work, the UK trade association for the interior landscaping industry, held its annual awards ceremony. Case studies of some award winners, e.g. SLG Cheltenham, Farfetch or Uncommon, Liverpool Street really show how such a design style is becoming more common.

These new ways of designing interior landscapes may present some challenges. Individual spaces in buildings may be used irregularly, which may mean inconsistent lighting and heating, which may affect the choice of plants used, or their maintenance schedules.

Other interior landscapers are looking towards putting their expertise in designing plant displays, using high quality plants and planters, to use to supply the growing number of houseplant enthusiasts as well as homeworkers missing their office greenery (good examples are In-tray Plants from Indoor Garden Design, or Foli8 from Planteria).

Technology and flexibility

Adapting to customers moving away from their traditional locations in city centres brings a number of logistical challenges. With customer density changing, service operations have to become more efficient. This is where technology offers some interesting opportunities.

Nurtio Technologies has developed an innovative system that combines a sensor (that measures soil moisture, temperature, light and nutrient levels) and a clever artificial intelligence algorithm that can help plan service schedules and alert the interior landscaper if there are sudden changes to the environment.

By learning the behaviours of individual plants (and groups of plants at the same location), the algorithm can predict when, and how much, water should be added and enable some flexibility in service schedules. One interesting opportunity that might arise, especially if access to buildings is tricky, or if plant displays are more dispersed as a result of a move to remote working, is that the business of watering plants can be delegated, leaving more time, or capacity, for skilled horticultural technicians to do the more complex parts of the job: pruning, grooming, pest/disease management and carrying out changes and re-designs.

UK interior landscapers needing more information about the benefits of the Nurtio system should get in touch with me.