While most people would assume that the increasing focus on energy efficient housing by home owners, builders, developers and governments is a good thing, some argue that it’s come with a trade-off.
According to building biologists, who are trained to assess, identify and quantify health hazards and irritants in indoor environments, our new energy-efficient homes could be making us sick. New homes are being built to strict air tightness standards that help to keep draughts out but make it more likely a home will trap humid air, enabling mould to spread.
The World Health Organisation (WHO) says mould is a key element in indoor air pollution and can cause respiratory symptoms, allergies and asthma.
Nicole Bijlsma established the Australian College of Environmental Studies to educate Australians about building biology and says a growing number of people are experiencing the symptoms of sick building syndrome (SBS) because new buildings are limiting the amount of fresh air coming inside.
SBS is where building occupants experience acute health and comfort problems that appear to be linked to time spent in a building.
“Policies at both the state and federal level aiming to improve the energy-efficiency of homes have improved insulation but they’ve led to buildings being constructed with tight thermal envelopes that have no passive ventilation,” says Nicole.
“While this is good for energy efficiency, it means there is no way for water vapour to move through the building envelope and therefore the buildings are completely dependent on heating and cooling systems. Research by the WHO found this causes a build-up of indoor pollutants that make occupants sick.”
With humans spending approximately 90% of their time indoors, the WHO says indoor air quality is the biggest cause of SBS.
According to Massey University’s Centre for Public Health Research, it’s estimated that 10%-20% of homes around the world are affected by some form of dampness.
“Moisture and damp are the main problems in regards to indoor air quality because as soon as there is moisture or high humidity levels at 60% or more in a building, mould and allergens such as dust mites proliferate,” says Nicole.
This doesn’t mean you shouldn’t be aiming to make your home as energy-efficient as possible though, and air tightness standards should still be followed. However, it’s important to keep in mind how our homes can affect our health.
The rising popularity of homes incorporating elements of passive design proves that we can build houses that are not only environmentally-friendly but that also provide a healthy environment for the occupants.
In the meantime, here are some ways you can improve the indoor air quality in your house now:
- Ventilation – Opening your windows for just five to 10 minutes per day either in the early morning or late evening is the simplest way to improve indoor air quality and circulation. You can also open windows when showering, bathing or cooking to encourage natural ventilation.
- Monitor humidity – Humidity should be kept to between 45% and 55% to reduce the risk of mould and other allergens building up. A dehumidifier will help reduce moisture if condensation is a problem in your home.
- Make use of plants – Some indoor house plants can act as air filters and purifiers, removing pollutants such as benzene, ammonia and formaldehyde from the air and supplying fresh oxygen. Nicole says plants also have the ability to maintain ideal humidity levels through transpiration via their leaves and evaporation from the soil and dishes.
- No shoes – Nicole says a no shoes in the home policy will help to reduce the amount of dust in the house by more than 50%.
- High Efficiency Particulate Air (HEPA) filter – Vacuum cleaners with HEPA filters trap 99.97% of a vacuum’s emissions down to 0.3 microns in size, ensuring particles do not become airborne.
- Regularly clean air vents – This will help to promote ventilation and is especially important in the kitchen and wet rooms.
