Skip to main content

                    Internal environment

                    Spacious open-plan office space with many indoor plants
                    A key focus of CH2's design is the indoor environment quality. In CH2, the air intake is 100 per cent filtered outside air, instead of being recycled such as in the traditional air-handling systems in most office buildings.

                    ​In addition to this, materials have been selected for qualities which minimise the harmful effects of off-gassing and indoor pollutants, such as Volatile Organic Compounds (VOCs).

                    Indoor plants have a proven role in the improvement of indoor air quality in office environments. There is at least one indoor plant per person in CH2.

                    CSIRO has undertaken indoor air quality tests during summer and winter conditions; in both assessments, the indoor air quality in CH2 for the weeks of assessment was rated as very good. See About Council House 2 to read the reports.

                    Air quality

                    The temperature of the air supplied to each floor vent in CH2 is approximately 20°C. Fresh air is released from the floor, with swirl diffusers located on movable floor tiles that allow individual placement to suit workstations. Air is only used once and is exhausted by natural convection to the atmosphere.

                    CH2’s air:

                    • is treated by filtering, heating or cooling and drying (if needed) in the plant room on the roof.
                    • is pumped from the roof plant room down the supply-air ducts (on the south side) and into the sub-floor space, which is a raised access-floor about 300mm high
                    • is brought into the office space via the circular outlets (‘swirl’ diffusers) located across the floor on the moveable floor tiles - these diffusers mix the air at low level
                    • rises as it heats up (from the heat generated in the office from people, lights, computers and so on), so the hot air is moved to the top of the office space
                    • finds its way, by natural convection, into the void formed by the ‘belly’ of the curved concrete ceiling - this void is connected to the exhaust-air shafts (located on the north side) by a short metal duct
                    • is exhausted to the atmosphere from vents at the top of the exhaust shafts beneath the yellow wind turbines on the roof.

                    This one-way air flow is called a ‘displacement’ air flow, which is of great benefit to staff because air that is exhaled rises and is, in turn, displaced by rising fresh air. This means staff are always breathing fresh air, rather than the mix of used and fresh air found in conventionally air-conditioned buildings.

                    There are two complete air changes every hour in CH2, which means there is about two-and-a-half times the amount of fresh air coming into the building, compared with most conventionally air-conditioned buildings.

                    This air system also means that the output from coughs and sneezes is being taken straight out of the building rather than being spread around the floor and around the building. This creates a healthy workplace.

                    Materials selection

                    Materials used in a building not only have an impact on environmental performance, they can also affect the health of its occupants. Materials considered for use in CH2 were evaluated for their environmental impact according to:

                    • their use and adherence to the principle of lowest lifecycle cost for the anticipated 100-year life: maximising durability, minimising replacement, maximising maintainability
                    • whether they minimise embodied energy
                    • whether they minimise indoor air pollutants
                    • their use of locally grown, sourced or manufactured products and materials.
                      Was this page helpful?

                      If you'd like to give more feedback or ask a question, please contact us.