Modern lifestyles and occupations mean we’re now spending more time than ever indoors, with the average person spending just one tenth of their time outside four walls. It’s also been found that the air inside a building can be up to 10 times more polluted than the air outside.
As a result, environmental bodies are increasingly encouraging architects to consider the extent to which the products and materials they specify could affect indoor air quality, both positively and negatively. In turn, architects are on the hunt for solutions that fit the bill and facilitate ‘healthier’ living and working spaces.
What the guidelines say
Over the past few years, organisations such as BREEAM, LEED and the International WELL Building Institute, which promote health and wellbeing in the built environment, have recognised indoor air quality within their standards. Among other requirements, their rating systems award points to projects that consider air pollution early in the design process and take measures to minimise it post-construction. For example, as of 2018, the BREEAM New Construction manual considers an Indoor Air Quality Plan a pre-requisite that must be completed at RIBA Stage 2.
Specifically, there are concerns around the indoor concentration of volatile organic compounds (VOCs), which are emitted as gases from certain solids or liquids. They include a variety of chemicals, some of which may have short- and long-term adverse health effects. One common VOC is formaldehyde, which can be present in houses and public spaces at varying concentrations, with molecules being emitted from a range of common indoor materials, such as chipboards, fibreboards, furniture, carpet, glue and interior fabrics. VOC levels have the potential to become harmful during the lifecycle of a building, so BREEAM awards further credit to those who can confirm concentrations are within defined guidelines at the post-construction phase.
There are various techniques that architects and designers can employ to achieve this and facilitate improved indoor air quality – some naturally-occurring, others a result of intensive research and product development. Here are just a few:
How to improve indoor air quality
Central heating and tightly closed windows reduce ventilation. One fairly simple way of improving indoor air quality, then, is by allowing outdoor air to dilute any indoor airborne pollutants. This can be achieved manually through appropriate placing of windows and doors, but opening these isn’t always practical for occupants, for example in commercial high-rise buildings. Alternative methods are therefore being encouraged for such circumstances. One such method is improving air intake through the HVAC system, with advanced designs including energy-efficient heat recovery ventilators.
Another cost-effective approach that’s received widespread publicity recently is the use of biophilic design – using plants and flowers in the spaces we live and work in to bring the outside in and help rekindle our innate connection to nature. Aside from the benefits related to psychological wellbeing, research has shown that plants clear the air of pollutants, reduce CO2 levels, increase oxygen and generally lift your energy. Taking this one step further, architects can install ‘living green walls’ that act as a bio-filter, often connected directly to a building’s HVAC setup.
Specifying natural materials such as wooden flooring is also a simple preventative measure. Wooden floors are much easier to maintain than carpets, which can harbor dirt, dust mites, hair, fungus and other potentially harmful particles.
Sometimes introducing more outdoor air, wooden floors and greenery just isn’t practical though. For these instances, there are a range of innovative materials and products that have been created by building product manufacturers. These products have been specifically designed to release fewer emissions, with some even having a positive effect on air quality. For example, architects can now specify carpet and flooring that not only emits fewer VOCs, but is also designed to capture ultra-fine dust particles and keep them out of the breathing zone.
Similar innovations have been developed when it comes to interior coatings and finishes. At PPG, our emulsion paints are all water-based and carry low VOC ratings, and we have recently launched Air Pure in the Johnstone’s Trade paint brand to specifically tackle formaldehyde, which can be damaging to health, causing headaches, tiredness and irritation of the nose, throat and eyes. Air Pure is a bio-based, low-VOC wall and ceiling paint that, once applied, purifies indoor air by neutralising up to 70% of formaldehyde from an indoor environment.
A healthier future
Huge leaps have been taken to improve indoor air quality over the past few years and the movement shows no signs of slowing down. As time goes on and people spend even more time indoors, what are now mostly recommendations and guidelines are sure to become stringent industry mandates. Now is therefore the time for architects to familiarise themselves with the various techniques and solutions they can implement, in order to improve the performance of their projects in line with environmental best practice and contribute to a healthier, more sustainable future.