The buildings and construction sector is a key actor in the fight against climate change: it accounted for 36% of final energy use and 39% of energy-and-process related emissions in 2017.

Great swathes of the Great Barrier Reef, once bathed in brilliant purple, red and blue, were suddenly bleached bone white in 2016 within a week, and again in 2017. Marine scientists attributed the devastating event to rising sea temperatures, a stark indication of climate change at work. It was nothing short of a national catastrophe.

Australia may have three of the most liveable cities in the world, but the country has been getting unbearably warm. Temperatures have risen by 0.9ºC since the 1960s, intensifying since 2005. Rainfall and drought are becoming extreme and these fluctuations are further cascading into, for example, toxic algae blooms forming and killing fish in the drought-hit Darling River.

Concerns about climate-related extinctions among Australians have risen from 71% in 2017 to 78% in 2019. Yet industries have been slow to adapt to changing public sentiment. Despite increasing support and political will to completely end coal-fired power generation, Australia remains one of the top 10 largest emitters of greenhouse gases (GHG) in the OECD.

Globally, the architecture, engineering and construction (AEC) sector is taking steps to tackle climate change while facing the near-term challenge of building more affordable housing for rapidly growing urban populations. Although research shows that the buildings and construction sector still accounts for 36% of global final energy use and nearly 40% of energy-related carbon dioxide (CO2) emissions, the tide is turning.

Emissions from the buildings and construction sector have levelled off since 2015 and is set to decrease steadily as it completes the transition towards clean energy. Energy demand growth between 2010 and 2017 was also less than floor area growth, indicating that energy demand may have decoupled from population growth.

The movement towards a more sustainable AEC sector is here to stay. What can individual companies do to incorporate sustainability in buildings?

“More than 4 billion tonnes of cement are produced every year, accounting for 8% of global CO2 emissions”

Building materials account for 28% of total buildings‐related CO2 emissions annually. Among the higher emitters are cement and steel - both emit high amounts of CO2 in the manufacturing process and are used in large quantities in most structures. Following close behind are aluminium, glass and insulation materials.

While cement and steel remain popular materials due to their strength, there has been growing interest in bio-based materials such as prefabricated cross-laminated timber (CLT) and bamboo. Rising prices of steel, together with increasing public backlash over the use of cheap, informal labour, has given further impetus for the AEC sector to deploy these new materials at pace.

Both International House Sydney and 25 King Street (Brisbane) were built with CLT, a material which has comparable strength to reinforced concrete. Developers say that the benefits of prefabricated CLT panels are threefold. It enables quicker construction using less labour, has about a quarter of the carbon footprint produced by conventional materials and adds to the biophilic nature of the building.

Bamboo is also making a comeback as a sustainable building material after falling by the wayside due to a perceived lack of durability and strength. Essentially a hardy grass, bamboo grows fast, taking only 3-5 years to reach maturity, and does not need to be replanted after harvesting. It sequesters carbon at a rate higher than any other plant on earth except seaweed. As a construction material, bamboo is lightweight, flexible, and strong. It also creates a char layer when exposed to fire, effectively serving as fire insulation.

“Energy use for ‘space cooling’ increased by 25% since 2010. There are now more than 1.6 billion air conditioning units in buildings globally.”

Air conditioning is responsible for more than 15% of global electricity demand growth. It is also responsible for 15% of the average global peak electricity load. This figure goes up as high as 50% on hot days in cities due to the urban heat island (UHI) effect. In keeping ourselves cool on amidst the growing heat we are ironically contributing to global warming.

Architects have begun incorporating passive cooling measures within building designs. One growing trend is creating a “green roof” or “green ”façade" with plants. This could reduce temperatures by 2-2.5ºC without air conditioning. While popular in Singapore and New York, vertical landscaping and rooftop gardens have yet to make an impact in Australia due to planning restrictions. Rooftop gardens are considered an additional storey to the building, which makes it difficult for developers to comply with acceptable rules for building heights.

Other elements of passive sustainable design include provision of daylight to reduce the need for artificial lighting, incorporating renewable energy sources such as solar power, providing natural cooling ventilation, as well as minimising energy demand for air conditioning through insulation, windows and air tightness.

“Processing power per dollar will increase a billion-fold within 30 years”

Smart cities are the future of the developed world. From data centres, citywide Wi-Fi, and IoT (internet-of-things) solutions such as smart lighting and energy management systems, city planners will be increasingly reliant on next-generation infrastructure to meet sustainability goals. AEC companies looking to play a role in that glimmering future must adapt to technological advances or be left behind.

7D BIM technology is already available. With it, builders can incorporate environmental impact data into the model at the early design stage of construction, creating more precise simulations in later stages of the project cycle. This enables energy savings to be planned and targeted with more accuracy, reducing the gap between predicted and actual green building performance.

Designers, for example, could select building materials based on quantifiable data as well as aesthetic. Information on the materials’ level of recyclability and resulting carbon footprint when demolished are some metrics that could be considered. This reduces both the embedded energy content of the building and makes the entire structure more sustainable as the materials could be reused or recycled.

Some AEC companies have begun integrating digital technologies at the workflow level. Cloud-based collaboration solutions and 24/7 connectivity have led to productivity gains through a reduction in missteps, miscalculations and ultimately less wastage in the field. Digital transformation is never an easy process, but technology partners that place priority on sustainability, in addition to productivity, will help make the shift easier.

Sustainability in architecture, engineering, and construction is here to stay. It is now up to AEC companies to adapt to the more eco-conscious global citizens of tomorrow.