Indoor Environment Quality
What is Indoor Environment Quality?
Indoor Environment Quality (IEQ) refers to the overall comfort of a building’s interior and the comfort and health of its occupants. Many factors may contribute to indoor environment quality, including the use of daylight, passive design and natural ventilation, air quality and indoor plants.
Research shows plants contribute to almost all factors of Indoor Environment Quality (IEQ) (*Criteria list – NSW Government Workplace Guidelines, website 2010). Therefore 6 out of 8 criteria are positively influenced by plants in the workplace.
- Ventilation Effectiveness: Increase effectiveness – remove CO2 and add O2.
- Lighting: If office’s levels are OK for plants, they will be beneficial for office staff.
- Low Emitting Materials: Absorb toxic emissions.
- Views: Add improved aesthetics and calming greenery.
- Noise: Absorb and buffer noise.
- Air Pollution Mitigation: Reduce all types of urban air pollution.
- Controllability of Systems: Not influenced.
- Thermal Comfort: Not influenced (However, plants do tend to stabilize humidity in human comfort range).
GBCA Green Star: IEQ-15
The Green Building Council of Australia’s Green Star Office Interior’s V1.1 includes indoor environment quality (IEQ). Section IEQ-15 is worth 2 points and relates to the use of indoor plants.
As described in the Technical Manual, quote:
“Research has found that indoor plants contribute to the health and wellbeing of building occupants.
The potted plant microcosm has been show to reduce air-borne concentrations of Volatile Organic Compounds (VOCs). Due to the large number of VOCs, indoor air concentrations are typically based on Total (TVOC) concentrations – essentially the sum of the individual concentrations.
The health effects of exposure to VOCs are consistent with Sick Building Syndrome effects – i.e. eye/nose/skin irritation, headache, lethargy, etc. These have been observed in subjects exposed to 1000 ppb and indoor air goals have been set to limit exposures to much lower levels.; in Australia the National Health and Medical Research Council (NHMRC) level of concern is 500 ug/m3 - approximately 100 ppb.
The research findings demonstrate that the ability of plants to metabolise Volatile Organic Compounds, increases with extended exposure to VOCs, provided the potted-plant system is kept in optimum condition.
The presence of indoor plants has also been show to decrease complaints of systems associated with respiratory illness and poor air quality. Several studies have shown lower workplace stress, a decrease in fatigue and enhanced productivity.”
Authors note – “An indoor environment good for plants is also good for people. Lots of fresh air, natural light (at levels necessary to support green life), a comfortable humidity and space to move.” In Brisbane we are blessed with the perfect climate and buildings should take advantage of the orientation of the sun and prevailing breezes.