Environmental Sustainability at K2

The K2 Apartments environmental sustainable design seeks to reduce the long-term negative environmental impact of buildings by making them energy and water-efficient and using non-toxic, recycled and reusable materials (such as recycled timber rather than that logged from old-growth rain-forests).

The K2 Apartments use simple, cost-effective design ideas that result in water and energy use and output. The buildings also make use of modern scientific solutions like solar power and water treatment.

The buildings are positioned on the property to receive maximum winter sun and use solar hot water. They are built with non-toxic materials (for example, all pipework is PVC free) and recycled and plantation timbers. The buildings have a built-in grey water recycling unit that is used for toilets and irrigation.

While the sustainable design features added 9 per cent to the cost of building the development, they will more than pay for themselves through water and electricity savings.


Rainwater is collected, treated and stored in rooftop tanks to supplement domestic supply. Grey water (wastewater from bathrooms, laundries and kitchens with low amounts of pollution) is recycled for gardening and toilet flushing.

Water-efficient fittings and fixtures such as AAA showerheads reduce water consumption, and water meters are installed in each unit to monitor water use and educate tenants. 'Water smart' gardens have been designed that need little water.

All these measures will reduce mains water use by approximately 53 per cent compared to an average apartment of similar size.


Materials were chosen because they were recyclable, robust, non-toxic, and did not produce much waste. Health of the environment, particularly of tenants, was an important consideration.

Timber was either reused or came from sustainable managed forests, and fly ash (a coal combustion product that is more durable and produces less greenhouse gas emissions than cement) was used instead of cement in concrete. Non-toxic paints and floor finishes were used, assuring high indoor air quality, while natural finishes reduce maintenance needs like painting and varnishing.

Energy use and solar power

The height, position and windows of the four buildings have been carefully chosen so that they are a comfortable temperature all year round.

Exposed concrete ceilings and heavy walls provide thermal mass to help maintain a stable temperature indoors, while insulation, double-glazed windows and shading prevent heat loss and gain. Energy-efficient fittings, such as fluorescent light bulbs, are installed throughout the apartments.


Cross-ventilation will cool the apartments and fans and ventilators will carry away built-up heat.


The buildings are oriented so that all units receive northern sun, reducing the need for heating. There are a limited number of windows on the south, east and west sides of the buildings to reduce heat loss through the glass. The buildings are well sealed and insulated, and screens beside the access balconies provide protection from the weather.

Solar power

Roof tops are angled to face the sun so that photovoltaic panels can collect the maximum amount of energy, and also provide some shade. Solar power heats at least 50 per cent of the buildings' hot water.


Approximately 20 per cent of the K2 site is dedicated to landscape gardens. 'Water smart' gardens drain water to areas where it is most needed, and filter stormwater before discharging it from the site. The gardens use drip irrigation from the grey water supply.

Mostly hardy native plants were chosen that suit Melbourne's dry conditions and the amount of sunlight in each space. A mixture of deciduous and evergreen trees was chosen to provide shade or allow sunlight in, as needed.

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