Working with Nature

Sustainable Infrastructure

Professor Janis Birkeland of the School of Architecture and Planning, National Institute of Creative Arts and Industries, University of Auckland and Adjunct Professor of Sustainable Design, Queensland University of Technology, supports this consensus in that, “Anything that is sustainable would have to make everyone better off, to make society better off, to give back to nature more than it takes.”

Janis concedes that in order for societies, cities and the built environment to be both sustainable and resilient, it is necessary to rethink building design, planning and construction to create net positive results. Net positive implies that buildings need to support their accompanying bioregions. But this ideology can be difficult to effect because construction methods and materials are by and large still focused on traditional and conventional concepts.

Positive Development theory maintains that the built environment can be fostered by continually increasing natural and social resources. Essentially, buildings can be retrofitted to give back to nature more than they take. “Retrofitting is unique. You can add on an interesting atrium that greatly improves energy efficiency, adds value to the building and makes indoor air much better… it pays for itself,” maintains Janis. These buildings can be net positive, generating their own eco-services, benefitting both nature and humans. Land use planning has to consider the importance of the natural environment and subsequently increase building efficiency on sites by using and harvesting water, energy and materials. These planned measures restore and protect not only the environment, but human health throughout the building’s life cycle. This applies to every aspect of building construction from site selection, design, and operation to maintenance, deconstruction and renovation.

Green Infrastructure vs Green Building

Oftentimes these two terms are used interchangeably, but they can refer to very different things. Green infrastructure involves planning in advance of the development of any structure and considers such things as designation for protection and restoration of land, treating storm water, securing wildlife habitat, energy savings and sustainable economies. It’s a “whole system” approach that’s resilient and efficient – an autonomous system that promotes the well being of occupants and the surrounding ecosystem. “There are buildings out there that are resource autonomous,” explains Janis. “They collect, use and treat their own energy and water… everything in ecological design is complex because it is site specific. It’s not something that lends itself to industrial mass production, although you could have some components that are mass produced and adaptable.”

Green building incorporates certification programs such as Leadership in Environment, Energy and Design (LEED), which determine energy efficiency standards in buildings, but oftentimes overlook or don’t consider the landscape. Although helpful, LEED doesn’t require interconnection to wildlife habitat or ensure that, for example, a site has maximum tree cover. Inappropriate sites may be selected that could more appropriately be preserved for groundwater recharge or green infrastructure uses. “People tried to develop rating tools to lift the bar and give certification to better buildings. In a way, those tools were based on traditional non-sustainable buildings. It had a tendency to encourage designers to make incremental improvements on the old building type, rather than looking at the pathologies of design that were actually sustainable,” says Janis. She believes that green buildings aren’t inherently sustainable and may do more harm than good; they replace nature. There has to be a shift from regenerative design toward eco-positive design. Traditional methods of construction are still using a lot of resources such as those extracted through mining and forestry. “A lot of it can be made much more low impact,” Janis asserts. “They’re not really thinking about anything beyond resources.”

Rethinking Building Design

According to the World Health Organisation, one third of new buildings cause Sick Building Syndrome. The Commonwealth Scientific and Industrial Research Organisation, (CSIRO), estimates that sick buildings cost Australia $12 billion per year. Globally, poor indoor air quality ranks fourth as a serious health problem. Indoor air can be more polluted than the air outdoors simply because indoor air carries both outdoor pollutants and toxic emissions from interior construction materials. “Many buildings have poor indoor air quality starting from the 70s when they started using insulation because of the oil crisis and cutting down on air changes… sick buildings are a big issue,” says Janis. Consequently, many buildings actually had to be demolished because occupants were getting sick.

Green Scaffolding

As an alternative, green scaffolding may be utilised to provide protection from weather elements such as wind, earthquakes and fires. By being connected to the structure, green scaffolding adds reinforcement and can extend the building’s life cycle. It can also be instrumental in promoting human health by improving air quality – reducing carbon dioxide and producing oxygen. Its design could heat, cool and provide ventilation to the building’s interior.

Living interior walls or ‘green walls’ are self sufficient vertical gardens that are attached to a building’s exterior or interior (see Construction in Focus March 2011). Living walls are essentially plant walls that remove contaminants such as volatile organic compounds (VOCs) and carbon dioxide from interior spaces through the capillary action of exposed root systems of tropical plants. This capillary action provides irrigation of a regulated water system. The bio filter process includes a basin that acts as a water reservoir and a plant support infrastructure. The backing on the plant wall also acts as a sound barrier. Living walls reduce energy costs through shading during the summer and insulating and trapping warmth in colder conditions.

Trombe Wall

A Trombe wall or solar wall is a sun-facing masonry wall that separates the outdoors by way of a glass panel and an air space that absorbs solar energy and releases it to the interior of a building. The wall acts essentially as a passive thermal collector, with open vents at the top and bottom of an interior wall that prevent night time convection so that heat flows into the building’s interior. During the summer the top vent is closed, creating a Solar Chimney that sucks air out of the building to the outside, allowing for ventilation. Because it is a passive system, a Trombe wall requires little maintenance and is relatively easy to install in existing or new construction. It can reduce energy costs compared to traditional methods of heating.

Green Roof

A Green Roof or eco-roof on a building can be partially or totally covered with vegetation and have an underlying waterproof membrane (see Construction in Focus July 2010). These roofs absorb rainwater and act as a natural habitat to wildlife, while at the same time reducing the urban heat island effect in cities. This effect is caused by tall buildings that restrict air flow, particulate and greenhouse gas pollution, and the accumulated waste heat produced by air conditioning and other energy demands. These elements combine to essentially trap heat during the day and release it slowly at night, making dense urban areas perpetually warmer than their surrounding rural areas. Heat related illnesses and even mortality can result.

Because green roofs protect the roof membrane, they last twice as long as a conventional roof, cutting down on maintenance and generating savings in replacement costs.

The Future of Green Infrastructure

The Australian Green Infrastructure Council is a principle player committed to more sustainable designs in the construction and operations of Australia’s green infrastructure planning. Its mandate is to develop standards and guidelines for infrastructure development that will create long time benefits to society. Sustainability is at the core of its philosophy and its infrastructure sustainability rating scheme (IS), is Australia’s only comprehensive rating system that assists in decision making for the future of sustainable development.

Janis emphasises that many of the damaging building design methods of the past can be corrected for the betterment of our planet by creating eco-positive environments. “In practice you could do a net positive building… you can predict the performance of these better designs. They indicate that they could sequester carbon and have positive health impacts.

“Things are changing quickly; it’s just a matter of time. Ten years ago people didn’t understand how cities and buildings were related to environment damage… I’m quite optimistic overall.”

Home Automation

Call it ‘domotics,’ and you are likely to receive a blank stare, but refer to it as ‘smart home’ or ‘home automation,’ and you will get a nod of acknowledgement. For the past few years, consumers have heard the word ‘smart’ attached to countless products and services, from food and drink to snacks like popcorn and mobile phones, which no one seems to refer to as a ‘cellphone’ anymore. Yet what, exactly, constitutes ‘smart’?

January 17, 2019, 5:37 AM AEDT