We have the blueprint for liveable, low-carbon cities. We just need to use it



Increasing heat in Sydney and other Australian cities highlights the urgent need to apply our knowledge of how to create liveable low-carbon cities.
Taras Vyshnya/Shutterstock

Deo Prasad, UNSW

Over the past seven years more than 100 research projects at the Co-operative Research Centre for Low Carbon Living, in collaboration with industry across Australia, have pondered a very big question: How do we build future cities that are sustainable, liveable and affordable?

This is exactly what Australians want, as the recent Greater Sydney Commission report, The Pulse of Greater Sydney, revealed. People want cities in which they live close to jobs and have reasonable commuting times. They want access to parks and green space, and relief from ever-increasing urban heat.




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The good news is we already know what it will take to deliver on much of this wish list. Since 2012, I have headed the A$100 million Low Carbon Living CRC, which has brought together Australian businesses, industries, communities and many of our brightest researchers to work out how to steer change.

Our Cooling Sydney Strategy, for instance, is the result of years of research into how to combat urban heatwaves. The burden of this heat is unevenly spread across our cities.

For example, residents of Sydney’s western suburbs are exposed to many more days hotter than 35 degrees than Sydneysiders living in the CBD and the city’s north. Last summer that meant over a month’s worth of intense heat in the suburb of Penrith, including nine days in a row above 35°C.




Read more:
Building cool cities for a hot future


While the recent winter sun might feel welcome, the negative impacts of increasingly hot cities on our health, lifestyle and energy use greatly outweigh any winter comfort.

So what are the solutions?

Our researchers have already found how we can offset increasing heat. The strategies includes cool and permeable pavements, water features and evaporative cooling, shade structures, vertical gardens, street trees and other plants – even special heat refuge stations.

Keeping cool inside, without huge power bills, is possible too. During last summer’s heatwave, our pilot 10-star energy-efficient house in Perth remained a comfortable 24°C inside, without air conditioning, when it was over 40°C outside. The exceptional thermal performance of the house was down to its evidence-based design.

Josh Byrne explains how his house keeps temperatures comfortable year-round with low energy use and no net emissions.



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When the heat is on, we need city-wide plans to keep cool


This work is just one part of our wider remit. Our UNSW-based centre is on track to deliver independently verified cuts of 10 megatonnes of carbon emissions generated by Australia’s built environment by 2020. By integrating renewable energy systems, smart technologies, low-carbon materials and people-centred design into buildings and urban precincts, we have developed a sustainable, liveable and affordable urban blueprint for Australia. A PwC study (yet to be released) estimated cumulative economic benefits totalling A$684 million by 2027.

To put this another way, we have identified and verified evidence-based pathways to cut emissions equivalent to taking some 2.1 million cars off the road.




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Cutting cities’ emissions does have economic benefits – and these ultimately outweigh the costs


Some of the progress to date is not immediately obvious to the casual observer. Take an otherwise unremarkable stretch of road along the back way to Sydney Airport. Recently, a 30-metre section of concrete was installed, which looks more like an ad hoc road repair than an important scientific pilot study.

Bu 15 metres is paved with a new geopolymer concrete that slashes greenhouse gas emissions by 50%. The other 15 metres is conventional concrete, the most widely used man-made material on the planet. Concrete production, using cement as its binder, accounts for about 8% of all global emissions.

The geopolymer concrete developed through our research centre is a similarly high-performance product but its binder safely incorporates otherwise noxious industrial waste streams, such as fly ash from coal-fired power stations and slag from blast furnaces. Australia has stockpiled about 400 million tonnes of waste from coal-fired power generation and steelmaking.

In Alexandria, in collaboration with the City of Sydney, we are testing this low-carbon concrete as a road surface that could help clean up industrial waste while slashing emissions. Working with NSW Ports, we’ve also shaped it into low-carbon bollards to form a breakwater to protect the coastline at Port Kembla from extreme weather.

Waste from coal-fired power stations has been used to make low-carbon bollards to protect the coastline at Port Kembla.

We now have the know-how to do better

There are many such success stories, but with 150 CRC Low Carbon Living projects the list is too long to detail. What’s more important, as our funding period comes to an end and Australia loses its only innovation hub committed to lowering carbon in the built environment, is to note how we got to where we are today.

The federal government’s Co-operative Research Centre program fosters co-operation and collaboration on a grand scale. Industries, businesses, government organisations and communities with a stake in solving big, complex challenges partner with researchers from a wide range of academic fields. This structure brings together sectors and people whose paths might otherwise rarely cross.

The cross-fertilisation of ideas, expertise and skills delivers innovative solutions. Research worldwide has consistently shown that collaboration drives innovation, and that innovation drives economic growth. Our experience confirms that as we partnered with organisations such as Multiplex, AECOM, BlueScope Steel, Sydney Water, ISCA, CSIRO and the United Nations Environment Program.

Cities are complex, exciting beasts, but we have the knowledge and expertise to live better, more comfortable urban lives in Australia while reducing demand for energy, water and materials. That is, we have the blueprint for low-carbon urban living. We must now choose to use it.


This article has been updated to correct the number of CRC Low Carbon Living projects to 150 and the amount of stockpiled waste from coal-fired power generation and steelmaking to 400 million tonnes.The Conversation

Deo Prasad, Scientia Professor and CEO, Co-operative Research Centre for Low Carbon Living, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Daylight robbery: how human-built structures leave coastal ecosystems in the shadows



Human-built structures are home to a wide variety of creatures.

Martino Malerba, Monash University; Craig White, Monash University; Dustin Marshall, Monash University, and Liz Morris, Monash University

About half of the coastline of Europe, the United States and Australasia is modified by artificial structures. In newly published research, we identified a new effect of marine urbanisation that has so far gone unrecognised.

When we build marinas, ports, jetties and coastal defences, we introduce hard structures that weren’t there before and which reduce the amount of sunlight hitting the water. This means energy producers such as seaweed and algae, which use light energy to transform carbon dioxide into sugars, are replaced by energy consumers such as filter-feeding invertebrates. These latter species are often not native to the area, and can profoundly alter marine habitats by displacing local species, reducing biodiversity, and decreasing the overall productivity of ecosystems.

Incorporating simple designs in our marine infrastructure to allow more light penetration, improve water flow, and maintain water quality, will go a long way towards curbing these negative consequences.

Pier life

We are used to thinking about the effects of urbanisation in our cities – but it is time to pay more attention to urban sprawl in the sea. We need to better understand the effects on the food web in a local context.




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Most animals that establish themselves on these shaded hard structures are “sessile” invertebrates, which can’t move around. They come in a variety of forms, from encrusting species such as barnacles, to tree-shaped or vase-like forms such as bryozoans or sponges. But what they all have in common is that they can filter out algae from the water.

In Australian waters, we commonly see animals from a range of different groups including sea squirts, sponges, bryozoans, mussels and worms. They can grow in dense communities and often reproduce and grow quickly in new environments.

The sheltered and shaded nature of marine urbanisation disproportionately favours the development of dense invertebrate communities, as shown here in Port Phillip Bay.

How much energy do they use?

In our new research, published in the journal Frontiers in Ecology and the Environment, we analysed the total energy usage of invertebrate communities on artificial structures in two Australian bays: Moreton Bay, Queensland, and Port Phillip Bay, Victoria. We did so by combining data from field surveys, laboratory studies, and satellite data.

We also compiled data from other studies and assessed how much algae is required to support the energy demands of the filter-feeding species in commercial ports worldwide.

In Port Phillip Bay, 0.003% of the total area is taken up by artificial structures. While this doesn’t sound like much, it is equivalent to almost 50 soccer fields of human-built structures.

We found that the invertebrate community living on a single square metre of artificial structure consumes the algal biomass produced by 16 square metres of ocean. Hence, the total invertebrate community living on these structures in the bay consumes the algal biomass produced by 800 football pitches of ocean!

Similarly, Moreton Bay has 0.005% of its total area occupied by artificial structures, but each square metre of artificial structure requires around 5 square metres of algal production – a total of 115 football pitches. Our models account for various biological and physical variables such as temperature, light, and species composition, all of which contribute to generate differences among regions.

Overall, the invertebrates growing on artificial structures in these two Australian bays weigh as much as 3,200 three-tonne African elephants. This biomass would not exist were it not for marine urbanisation.

Colonies of mussels and polychaetes near Melbourne.

How does Australia compare to the rest of the world?

We found stark differences among ports in different parts of the world. For example, one square metre of artificial structure in cold, highly productive regions (such as St Petersburg, Russia) can require as little as 0.9 square metres of sea surface area to provide enough algal food to sustain the invertebrate populations. Cold regions can require less area because they are often richer in nutrients and better mixed than warmer waters.

In contrast, a square metre of structure in the nutrient-poor tropical waters of Hawaii can deplete all the algae produced in the surrounding 120 square metres.

All major commercial ports worldwide with associated area of the underwater artificial structures (size of grey dots) and trophic footprint (size of red borders). Trophic footprints indicate how much ocean surface is required to supply the energy demand of the sessile invertebrate community growing on all artificial structures of the port, averaged over the year. This depends on local conditions of ocean primary productivity and temperature. Ports located in cold, nutrient-rich waters (dark blue) have a lower footprint than ports in warmer waters (light blue).

Does it matter?

Should we be worried about all of this? To some extent, it depends on context.

These dense filter-feeding communities are removing algae that normally enters food webs and supports coastal fisheries. As human populations in coastal areas continue to increase, so will demand on these fisheries, which are already under pressure from climate change. These effects will be greatest in warmer, nutrient-poor waters.

But there is a flip side. Ports and urban coastlines are often polluted with increased nutrient inputs, such as sewage effluents or agricultural fertilisers. The dense populations of filter-feeders on the structures near these areas may help prevent this nutrient runoff from triggering problematic algal blooms, which can cause fish kills and impact human health. But we still need to know what types of algae these filter-feeding communities are predominantly consuming.




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Our analysis provides an important first step in understanding how these communities might affect coastal production and food webs.

In places like Southeast Asia, marine managers should consider how artificial structures might affect essential coastal fisheries. Meanwhile, in places like Port Phillip Bay, we need to know whether and how these communities might affect the chances of harmful algal blooms.The Conversation

Mussels in the port of Hobart.

Martino Malerba, Postdoctoral Fellow, Monash University; Craig White, Head, Evolutionary Physiology Research Group, Monash University; Dustin Marshall, Professor, Marine Evolutionary Ecology, Monash University, and Liz Morris, Administration Manager, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Don’t forget our future climate when tightening up building codes



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Australia’s new National Construction Code doesn’t go far enough in preparing our built environment for climate change.
Sergey Molchenko/Shutterstock

Deo Prasad, UNSW

Too often it takes a crisis to trigger changes in legislation and behaviour, when forward thinking, cooperation and future planning could have negated the risk in the first place. Australia’s building and construction industry is under the microscope and changes in the law are in the wind, due to situations that could have been avoided. These include the evacuation of Sydney’s Opal building and the fires in Melbourne’s Lacrosse tower in 2014 and the Neo200 apartment building in February, both of which were fuelled by combustable cladding, as was the 2017 fire in London’s Grenfell Tower that killed 72 people.

The Shergold Weir report made 24 recommendations to improve the National Construction Code to ensure compliance, integrity and more. Commissioned by federal and state building ministers, the report was made public at the Australian Building Ministers Forum in April 2018. But implementation has been too slow to prevent the problems in the Opal and Neo200 apartment buildings. And it included no changes to climate-proof buildings.




Read more:
Australia has a new National Construction Code, but it’s still not good enough


A new National Construction Code comes into effect on May 1. Recent events have, however, exposed inadequate construction standards and increased public pressure for further change. This presents an opportunity to future-proof our cities as well as restore public confidence in our construction industry.

Construction codes were created to eliminate “worse practice”, but we are now in a position to make them “best practice”. Importantly, we must prepare for climate change. Australia is increasingly experiencing more extreme weather patterns, but are we ready?

The legislative overhaul must also include building sustainability and higher performance requirements. A low-to-zero-carbon future must be part of the picture.

Construction code changes are needed urgently, not just for increased safety, but to ensure future urban developments:

  • are ready for higher energy demands to cool and heat buildings
  • are designed to maximise sun and shade at the appropriate times to cool and warm both building and street
  • use materials that reflect heat for hot climates and absorb it for cooler ones
  • maximise insulation to reduce energy use
  • provide enough green space to give shade, produce oxygen and sustain a healthy environment
  • use water features to cool common and public areas
  • install smart technology to monitor and manage buildings and precincts.



Read more:
As climate changes, the way we build homes must change too


Many leading developers are taking the initiative to ensure projects include high-performance, zero-carbon, highly energy-efficient buildings, with top star ratings, but action needs to be across the board. This can only be done via tough legislation and enforced compliance.

The University of NSW’s Tyree Building is an excellent example of a high-performance building, as is One Central Park, Sydney, which features hanging gardens and an internal water recycling plant. But its most striking feature is its “heliostat”, a large array of mirrors that reflect sunlight to areas that would otherwise be in shadow.

One Central Park.
SAKARET/Shutterstock

Around the world, high-performance buildings are on the increase, such as 313@Somerset in the heart of Singapore, and the Sohrabji Godrej Green Business Centre in Hyderabad – India’s first Leadership in Energy and Environmental Design (LEED) platinum-rated building. There are many more.

Changing the law

New building standards and compliance are required to ensure high-performance buildings are the norm, not the exception. The construction industry should fulfil a “cradle to cradle” objective for materials. This means accounting for:

  • where materials come from
  • how materials are made
  • safety levels
  • carbon component
  • recyclability at demolition.

Laws covering low-carbon building design are imperative, setting standards for geography, maximising natural light, air flow, insulation and smart technology. Technology can monitor and run a building’s utilities to ensure it’s not only energy-efficient but also delivers a health standard that’s adaptable to the future pressures of climate change.




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Green buildings must do more to fix our climate emergency


Sustainable buildings are achievable now

Current know-how makes all this achievable. Over the past seven years the Cooperative Research Centre for Low Carbon Living and its industry partners have funded research into most low-to-zero-carbon aspects of the built environment. This has led to many recommendations in reports like Built to Perform, produced by the Australian Sustainable Built Environment Council.

The many research projects include:

  • 17 living laboratories providing cutting-edge data
  • creating low-carbon communities
  • developing tools to measure carbon outputs, from materials to services
  • studying the effects of heatwaves in Western Sydney and ways to cool cities
  • research into low-carbon concrete made of fly ash.

This plethora of data reveals that sustainable cities and precincts are achievable, while providing for a growing communities. Blockchain and solar technology, for example, is now proven for managing a precinct’s energy needs and can help turn energy users into providers.




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Although we are more global than ever, online and social media have in turn made us locally focused. We can know what’s going on in our street at a click and this technology is applicable to the operation of our future, sustainable cities.

We have the data, expertise, tools and knowledge to make safe, low-to-zero-carbon cities part of our future. But there’s much work to do. We still need to implement this knowledge, use the tools, change behaviour and instil 100% trust in the design and construction process. There’s no time to waste.The Conversation

Deo Prasad, Scientia Professor and CEO, Co-operative Research Centre for Low Carbon Living, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Buildings produce 25% of Australia’s emissions. What will it take to make them ‘green’ – and who’ll pay?


Igor Martek, Deakin University and M. Reza Hosseini, Deakin University

In signing the Paris Climate Agreement, the Australian government committed to a global goal of zero net emissions by 2050. Australia’s promised reductions to 2030, on a per person and emissions intensity basis, exceed even the targets set by the United States, Japan, Canada, South Korea and the European Union.

But are we on the right track to achieve our 2030 target of 26-28% below 2005 levels? With one of the highest population growth rates in the developed world, this represents at least a 50% reduction in emissions per person over the next dozen years.




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Consider the impact of one sector, the built environment. The construction, operation and maintenance of buildings accounts for almost a quarter of greenhouse gas emissions in Australia. As Australia’s population grows, to an estimated 31 million in 2030, even more buildings will be needed.

In 2017, around 18,000 dwelling units were approved for construction every month. Melbourne is predicted to need another 720,000 homes by 2031; Sydney, 664,000 new homes within 20 years. Australia will have 10 million residential units by 2020, compared to 6 million in 1990. Ordinary citizens might be too preoccupied with home ownership at any cost to worry about the level of emissions from the built environment and urban development.

What’s being done to reduce these emissions?

The National Construction Code of Australia sets minimal obligatory requirements for energy efficiency. Software developed by the National Housing Rating Scheme (NatHERS) assesses compliance.

Beyond mandatory minimum requirements in Australia are more aspirational voluntary measures. Two major measures are the National Australian Built Environment Rating System (NABERS) and Green Star.

This combination of obligatory and voluntary performance rating measures makes up the practical totality of our strategy for reducing built environment emissions. Still in its experimentation stage, it is far from adequate.

An effective strategy to cut emissions must encompass the whole lifecycle of planning, designing, constructing, operating and even decommissioning and disposal of buildings. A holistic vision of sustainable building calls for building strategies that are less resource-intensive and pollution-producing. The sustainability of the urban landscape is more than the sum of the sustainability of its component buildings; transport, amenities, social fabric and culture, among other factors, have to be taken into account.

Australia’s emission reduction strategy fails to incorporate the whole range of sustainability factors that impact emissions from the built environment.

There are also much-reported criticisms of existing mandatory and voluntary measures. A large volume of research details the failure of voluntary measures to accurately evaluate energy performance and the granting of misleading ratings based on tokenistic gestures.




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On top of that, the strategy of using front runners to push boundaries and win over the majority has been proven ineffective, at best. We see compelling evidence in the low level of voluntary measures permeating the Australian building industry. Some major voluntary rating tools have penetration rates of less than 0.5% across the Australian building industry.

As for obligatory tools, NatHERS-endorsed buildings have been shown to underperform against traditional “non-green” houses.

That said, voluntary and obligatory tools are not so much a weak link in our emission reduction strategy as the only link. And therein lies the fundamental problem.

So what do the experts suggest?

We conducted a study involving a cohort of 26 experts drawn from the sustainability profession. We posed the question of what must be done to generate a working strategy to improve Australia’s chances of keeping the carbon-neutral promise by 2050 was posed. Here is what the experts said:

Sustainability transition in Australia is failing because:

  • government lacks commitment to develop effective regulations, audit performance, resolve vested interests (developers), clarify its own vision and, above all, sell that sustainability vision to the community

  • sustainability advocates are stuck in isolated silos of fragmented markets (commercial and residential) and hampered by multiple jurisdictions with varied sustainability regimes

  • most importantly, end users just do not care – nobody has bothered to communicate the Paris Accord promise to Joe and Mary Citizen, let alone explain why it matters to them.

Tweaking the rating tools further would be a good thing. Getting more than a token few buildings rated would be better. But the show-and-tell display of a pageant of beautiful, green-rated headquarters buildings from our socially responsible corporations is not going to save us. Beyond the CBD islands of our major cities lies a sea of suburban sprawl that continues to chew up ever more energy and resources.




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It costs between 8% and 30% more than the usual costs of a building to reduce emissions. Someone needs to explain to the struggling home owner why the Paris climate promise is worth it. Given the next election won’t be for a few months, our political parties still have time to formulate their pitch on who exactly is expected to pay.The Conversation

Igor Martek, Lecturer In Construction, Deakin University and M. Reza Hosseini, Lecturer in Construction, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Working with nature can help us build greener cities instead of urban slums



File 20180622 26558 1aykrte.jpg?ixlib=rb 1.1
Garden roofs (like these in Chengdu, in China’s Sichuan province) need maintenance and community involvement.
from shutterstock.com

Paul Osmond, UNSW

As Australian cities grow and transform, we need to ensure we are not building the slums of the future by making buildings so tall and tight they turn our streets into stark canyons. Sydney’s Wolli Creek, where buildings dominate and tower over a transport hub, is an example of where this is happening. It is now considered one of the city’s densest areas.

Dense, high buildings limit the space available for urban greenery and, unfortunately, the current development boom privileges concrete and glass over vegetation. A more strategic approach to urban growth can ensure our cities maintain adequate green space and become low-carbon, efficient and affordable.

It’s also vital the community and individuals are enthusiastic drivers of such change, with shared ownership of it. Imaginative projects – at times described as urban acupuncture – can all play a role. This is where small-scale interventions (like green balconies) are applied to transform the larger urban context, improve the environment and make the city liveable.




Read more:
Higher-density cities need greening to stay healthy and liveable


Going up or out

Whether you go up (higher) or out (more), or both, there are always challenges and opportunities.

The drawback in going out is that we start creeping into our remaining open space, including important biodiversity hotspots.

Sydney’s Wolli Creek is considered one of the city’s densest areas.
from shutterstock.com

Going out can also encroach on agricultural land. Farmers around the Sydney basin produced up to 20% of the area’s fresh food needs in 2011. But researchers have predicted urban sprawl and rising land prices will lead this to drop to 6% by 2031, losing both produce and jobs.

Going up is an approach driven by proximity to transport, utilities and employment, particularly in Sydney and Melbourne. Major upward developments, like Wolli Creek, are logically being located around transport nodes. But these then become dense and concentrated areas, putting growing pressure on open space and community facilities.

Community projects

Community consultation is key before any major project and redevelopment, as genuine dialogue supports shared ownership of the outcomes. Existing community projects must be celebrated. Having an engaged and empowered community leads to a healthier, happier population.




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In Sydney, new precincts like Waterloo are ambitious and have good intentions. These areas aim to deliver new homes, shops, major transport services, community facilities, parks and open spaces over the next 20 years – and they’re located close to the urban centre.

Waterloo already has three community gardens, which bring together public housing residents through growing and sharing fresh produce. This approach is important to continue and initiate new projects.

Green roofs can become community gardens.
from shutterstock.com

Around the world there have also been successes with city farming where the community grows and sells agricultural produce locally. In skyscraper Singapore, they are farming vertically at Sky Greens, providing an alternative to importing food for this densely peopled city-state.

Green roofs are another alternative where communities can grow flowers and vegetables while providing training and jobs. A good example is the Uncommon Ground rooftop farm in Chicago.




Read more:
Australian cities are lagging behind in greening up their buildings


In Australia, the Grounds is a former pie factory in the industrial heart of Sydney’s Alexandria. In 2012, the site began to metamorphose into a cafe, restaurant, bakery, organic mini-farm and more. This is a successful example of how a little greenery has turned a bleak post-industrial site into an enjoyable destination, where young and old from far and wide come to enjoy the plants, animals and coffee.

The Grounds in Sydney’s Alexandria was transformed from an industrial site into an enjoyable destination.
Herry Lawford/Flickr, CC BY

A domestic garden, a green balcony or a green wall can all play a role – but these need ongoing care and attention, which means individuals and engaged communities must drive the enthusiasm.

Nature in the city

So, for a start, let’s not build fast and furiously without grasping the place as a whole and making the most of what is already there. This means preserving mature trees and shrubs, leaving open space unpaved and protecting areas of deep soil for future planting.

Maintaining, enhancing and creating urban green space not only fulfils the requirements for urban acupuncture, but – to mix medical metaphors – provides a kind of urban vaccination against the emergence of slums, where nothing can grow and depression sets in.

The ConversationWe can combine building development with what Stefan Boeri Architects have described as “vertical densification of nature within the city” to achieve a new kind of urban nature – nature in the city to transform the nature of the city.

Paul Osmond, Senior Lecturer and Director, Sustainable Built Environment program, UNSW

This article was originally published on The Conversation. Read the original article.

Australian cities are lagging behind in greening up their buildings


File 20180620 137734 1d98wbz.jpg?ixlib=rb 1.1
Green rooftops give a backyard feel to smaller housing units in Sydney
Author Provided , Author provided

Sara Wilkinson, University of Technology Sydney; Paul J Brown, University of Technology Sydney, and Sumita Ghosh, University of Technology Sydney

Covering roofs and walls of buildings with vegetation is a good way of reducing greenhouse gas emissions. And these green roofs and walls make cities look nicer. Toronto’s central business district adopted a policy of establishing green roofs on around half of all city buildings in 2009. Research shows this could reduce maximum city temperatures by up to 5℃.

We spent the past 12 months analysing the case for more greenery on Australian city buildings, drawing on international comparisons. We’ve shown that a mandatory policy, coupled with incentives to encourage new and retrofitted green roofs and walls, will provide environmental, social and business benefits.




Read more:
Green roofs and walls – a growth area in urban design


These include improved air quality, energy conservation and reductions in stormwater run-off from buildings, which would decrease flash flooding. Green roofs and walls also become new habitats for biodiversity and can be pleasant spaces for social interaction in dense urban areas.

We found numerous studies confirming that greenery on inner-city buildings reduces the urban heat island effect, which is when city centres are hotter than surrounding suburban and outer-urban areas.

Green roofs are great social spaces.
Author provided, Author provided

What other countries are doing

We examined international case studies of cities embracing green roofs and walls to review policy frameworks which could be suitable for Australia. A range of measures and policies exist and vary depending on building types (buildings need specific features to host vegetation) and the degree to which policies can be enforced.

Singapore is leading in this area. It markets itself as a “garden city” to attract investment, visitors and commerce. Green roofs and walls are a vital and visual manifestation of this policy.

Green walls are aesthetically pleasing.
Author provided

Greenery is ingrained in Singapore’s development sector and is boosted by incentives, grants, awards, certification schemes and government-led development. Through this voluntary-heavy (yet supported) effort, Singapore increased its number of green roofs and spaces nine-fold between 2006 and 2016.

Rotterdam’s efforts weren’t as extensive as Singapore’s, but the city more than doubled its green roof area from 2012-2017 through incentives, grants, tax benefits and demonstration projects.

London increased its total green-roof area more than four-fold from 2005-2016. This was partially achieved through a biodiversity action plan.

And Toronto has the second-largest area of green roofs of the four cities we studied. This has been delivered through a mandatory policy, introduced in 2009, that requires all new developments with roofs of 2,000m² or more to install green roofs.

The case in Australia

We modelled what could be delivered in the City of Sydney and the City of Melbourne based on the measures taken in Singapore (which is voluntary-heavy), London (voluntary-light), Rotterdam (voluntary-medium) and Toronto (mandatory).

We combined this with data on actual green building projects in 2017 in Sydney and Melbourne to show the potential increase of projects in each city based on the four policies.

In the Sydney local government area, 123 green roof and wall projects were under way in 2016. The below table uses this base to estimate what the numbers of such projects would be for three time periods, based on the policies in the four scenarios modelled.

https://datawrapper.dwcdn.net/7ff2z/3/

In the Melbourne local government area, 28 green roof and wall projects were under way in 2016. The table below shows how these could increase based on policies of the four case studies modelled.

https://datawrapper.dwcdn.net/s2Efy/1/

How Australia can get on board

Sydney and Melbourne have green roof and green wall policies aligned with their 2030 and 2040 sustainability targets, launched in 2012 and 2015 respectively. Sydney has the Green Roofs and Walls Policy Implementation Plan, while Melbourne has the Growing Green Guide 2014.

These policies appear most aligned with the voluntary-light approach adopted in London. Sydney had a 23% increase in green roofs since its policy launch, although this was from a very low starting point. Melbourne also reports an increase in green roofs and walls, though the amount of uptake isn’t publicly available.

There are, of course, barriers to greening up buildings. These include costs as well as lack of experience in the industry, especially in terms of construction and management. Professional capacity for green roofs is still in a developing phase and further training and skill development are needed.

Green wall adds vegetation to an aged care home in Sydney.

Around 87% of the building stock Australia will have in 2050 is already here, and a large proportion of existing buildings could be retrofitted. We recommend a voluntary approach using a mix of initiatives for building owners, such as tax benefits and credits in green building tools.




Read more:
If planners understand it’s cool to green cities, what’s stopping them?


Focusing on new buildings is likely to lead to more modest growth rates in the short to medium term, relative to alternative approaches such as retrofitting. The annual growth rate of new stock is around 1-3%, which means that policies focusing on new stock will have a substantial impact over the long term.

However, in the short to medium term, a retrofit policy would have greater impact given the numbers of existing buildings suitable for this.

The ConversationLocal government areas can also promote the evidence showing the lift in property values in areas with more green infrastructure – in some instances up to 15%. This should encourage voluntary uptake.

Sara Wilkinson, Associate Professor, School of the Built Environment, University of Technology Sydney; Paul J Brown, Senior Lecturer – Creative Intelligence | Faculty of Transdisciplinary Innovation & Senior Lecturer – Accounting | UTS Business School, University of Technology Sydney, and Sumita Ghosh, Senior Lecturer, School of the Built Environment, University of Technology Sydney

This article was originally published on The Conversation. Read the original article.

Scientists create new building material out of fungus, rice and glass


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Fungal bricks have the potential to create safer and more sustainable buildings.
V Anisimov / Shutterstock

Tien Huynh, RMIT University and Mitchell Jones, RMIT University

Would you live in a house made of fungus? It’s not just a rhetorical question: fungi are the key to a new low-carbon, fire-resistant and termite-deterring building material.

This type of material, known as a mycelium composite, uses the Trametes versicolor fungus to combine agricultural and industrial waste to create lightweight but strong bricks. It’s cheaper than synthetic plastics or engineered wood, and reduces the amount of waste that goes to landfill.




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What a fun guy

Fungal brick prototypes made from rice hulls and glass fines waste.
Tien Huynh, Author provided

Working with our colleagues, we used fungus to bind rice hulls (the thin covering that protects rice grains) and glass fines (discarded, small or contaminated glass). We then baked the mixture to produce a new, natural building material.

Making these fungal bricks is a low-energy and zero-carbon process. Their structure means they can be moulded into many shapes. They are therefore suited to a variety of uses, particularly in the packaging and construction industries.

A staple crop for more than half the world’s population, rice has an annual global consumption of more than 480 million metric tonnes and 20% of this is comprised of rice hulls. In Australia alone, we generate about 600,000 tonnes of glass waste a year. Usually these rice hulls and glass fines are incinerated or sent to landfill. So our new material offers a cost-effective way to reduce waste.

Fire fighter

Fungal bricks make ideal fire-resistant insulation or panelling. The material is more thermally stable than synthetic construction materials such as polystyrene and particleboard, which are derived from petroleum or natural gas.

Rice hulls, glass fines and the mixture of rice, glass and fungus, before baking.
Wikipedia/Tien Huynh, Author provided

This means that fungal bricks burn more slowly and with less heat, and release less smoke and carbon dioxide than their synthetic counterparts. Their widespread use in construction would therefore improve fire safety.

Thousands of fires occur every year and the main causes of fatalities are smoke inhalation and carbon monoxide poisoning. By reducing smoke release, fungal bricks could allow more time for escape or rescue in the event of a fire, thus potentially saving lives.




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Bug battler

Termites are a big issue: more than half of Australia is highly susceptible to termite infestations. These cost homeowners more than A$1.5 billion a year.

Our construction material could provide a solution for combating infestations, as the silica content of rice and glass would make buildings less appetising to termites.




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The use of these fire-and-termite-resistant materials could simultaneously revolutionise the building industry and improve waste recycling.

Figure 3. Termite infestation zones in Australia.
termitesonline.com.au, Author provided

This is an exciting time to get creative about our waste. With China no longer buying Australia’s recycling – and new rules reducing plastic use in Australian supermarkets – we have the chance to move in line with communities in Japan, Sweden and Scotland that have near-zero waste.

Fungal bricks could be just one example of the creative thinking that will help us get there.


The Conversation


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Tien Huynh, Senior Lecturer in the School of Sciences, RMIT University and Mitchell Jones, PhD Student, RMIT University

This article was originally published on The Conversation. Read the original article.