How does one determine if a building is indeed green? Can this be resolved without running its specifications through a computer database or applying for a star rating? By adhering to a few eco-design principles, Warren McLaren believes a building could be considered environmentally responsible if:
ppropriately located
Choosing location is one decision that has a significant impact on how green a building is. A building does not exist in isolation. It is more a base camp, with occupants making constant forays elsewhere for work, school, shopping, recreation, family life and so on. The distance a building is from these activities determines how much travel its inhabitants will make. As the world’s largest per capita emitter of greenhouse gases, this is an important consideration for the greening of Australian buildings. According to research from Flinders University, which looked at commuting patterns in Sydney, Melbourne, Brisbane, Adelaide and Perth, two-thirds of Australians, on average, drive their private cars to work. Whereas previously our towns and cities evolved along transport corridors (where the train, tram and bus went, so did the houses and buildings), this is no longer true. Yet the most resilient communities are those where people can walk to the park, school, shops, train station, etc.
Resource efficient
A life cycle assessment by Belgium’s Department of Architecture, Urbanism and Spatial Planning observed that were a building to last for 75 years, between 70 per cent and 75 per cent of its energy consumption would occur not in construction, but in the use phase — and that didn’t even cover the building’s lighting. A University of Michigan project similarly found that almost 94 per cent the energy required by an average American house was chewed up during the home’s use. Research undertaken by Bluescope Steel also determined that the energy embodied in the building materials is small — around 3 per cent — when compared with the energy used to operate it over its life. None of this is to suggest designers shouldn’t carefully consider the materials they specify — they should — but the salient point here is that we significantly leverage our designs when buildings are highly efficient in use, minimising the resources and energy they’d otherwise consume for heating, cooling and lighting.
Well orientated
Orientation is crucial for passive solar design, that trick of heating and cooling buildings without additional energy inputs. But orientation is so much more than getting winter sun penetration. Where possible, roofs should be arranged so they optimise photovoltaic electricity and/or hot water systems. One of the core principles of permaculture design is to observe and learn from the land, a process that should apply equally to architecture. Not only where the sun will fall onto the building, but how will air pass over and through it? Where will bushfire danger come from and how can it be mitigated? Are gardens best placed in relationship to dwellings? Can buildings be positioned or sculptured to maximise water retention on-site? Is access appropriate for less mobile inhabitants and visitors? Do recovering hospital patients, or long suffering office workers, have views of therapeutic trees or foliage? These issues all need to be addressed to attain the perfect orientation for passive solar design.
Waterwise
Were you a building, your species would be greedily slurping up to 17 per cent of the world’s fresh water supplies. We know that Australia has been enduring its longest, hottest drought since records began in 1900. With clever, creative eco-design, buildings need not be so thirsty. In fact, they could be collecting more water than they guzzle. Rainwater harvesting is now quite advanced, with a vast array of water storage options for pretty much any type of building. Greywater systems are evolving at a fast rate of knots and importantly, clients now expect them in their buildings. Stormwater retention design has been charging along as well, especially with developments in landscaping that merge vehicle supporting surfaces with soil and ground cover vegetation. Planning authorities, technical product innovation and client demand are now all in agreement: green buildings are no longer simply about energy efficiency, they’re also about being highly water wise.
Adaptable
The first question for a green building should be do we need to build one? Is it possible that an existing building can be adapted or converted to suit the client’s needs? A study by the Building Research Association of New Zealand (BRANZ) concluded that in terms of life cycle costs, the preferred option is to renovate and extend the life of an existing house for another 30 years than to replace it, even if the replacement building was designed for optimal orientation and passive solar. When a new building is required, it’s vital that its design can accommodate different needs and uses in the distant future. The BRANZ report noted a study which found that buildings should be able to last 210 years if well maintained and rehabilitated throughout their lives. Central tenements of any eco-design is that it exhibits longevity, durability and an ability to be repaired/restored.
Cyclic
Buildings chomp down on one quarter of the annual global wood harvest, according to the US LCA Center. Our own Department of the Environment once calculated that between 30 per cent to 40 per cent of Australian landfill waste is made up of construction and demolition materials. In NSW alone, 55 per cent of the 1.5 million tonnes of building waste is from demolition work. We’ve been digging holes in the ground to extract materials, only to dig more holes to bury them — a very linear view and what Interface chairman and eco-pioneer, Ray Anderson, terms ‘Take, Make, Waste.’ For a building to be considered green it needs to ensure its inputs can become what architect William McDonough calls industrial and natural nutrients. A green building will convert toilet waste into compost and plasterboard offcuts into new plasterboard. It’ll employ renewable materials like timber and cork, as well as finishes like linseed and citrus oil — its component parts will essentially be landfillphobic.
Small
Small is beautiful — a smaller building will use less materials to construct. Fewer materials translates to less ecosystems and biodiversity being disturbed via the resource extraction needed to make them and less carbon dioxide emitted in producing and transporting materials. Small spaces are also far easier to heat, cool, light and clean, thus reducing energy loads. The Australian Bureau of Statistics notes that during the past 20 years, the floor area of Australian houses grew 32 per cent, even though the family size decreased. A smaller building footprint, particularly in housing, allows for more land to be kept aside for the essentials of civilised society, such as food production and recreation. Likewise, it can assist in minimising urban sprawl, which if left unchecked, creates unsustainable demand on infrastructure services like schools, post offices and roads. But small doesn’t have to be synonymous with crowded. Handled with finesse, it can denote snug and cosy.
Local
Whether clichéd or not, the adage “Think global, act local” remains valid. By sourcing materials closer to home we’re more likely to scrutinise our own resource extraction than we are if our timber is coming from Asia, or our marble from Europe. Now it may be that goods shipped from Europe by sea generate less carbon dioxide than those trucked long haul by road within Australia, but that does not negate the reality that we’re still resource and energy gluttons (Australia’s ecological footprint is 7.8 hectares per capita, compared to the global average of 2.7 hectares). Another way that thinking local invokes better environmental outcomes is by respecting vernacular design. Take for example the Queenslander building, whose design predates widespread use of energy hogging air-conditioning by maximising ventilation and airflow in hot and humid environs, yet minimises the impact of frequent flooding. By relating our buildings to their local climate, landform and culture we encourage their users to connect with the structure.
