In New Zealand, there are many reasons for implementing sustainable practices in the construction industry. Indeed, the concept of sustainability in the New Zealand construction sector goes far beyond environmental considerations.
As well as the acceleration of climate change and global warming, there are other factors such as supporting sustainable working conditions for workers, maintaining financial sustainability, respecting Māori cultural values, and being mindful of the needs of a multicultural workforce.
For construction students and workers in New Zealand, there are four pillars of sustainability to address, explains Capable NZ’s Senior Construction Lecturer and Facilitator, Dr Don Samarasinghe. These are also known as the Four Ps.
This is probably the most prominent pillar in terms of how people think of sustainability, and it is highly relevant to the construction sector.
“The construction industry has a staggeringly high carbon footprint, accounting for one-third of the world’s carbon dioxide emissions,” says Dr Samarasinghe. “This is largely because it requires so much energy in the manufacturing process, and the transportation, installation and demolition of materials.”
He says one significant way to combat this is to use building materials that consume less energy – for example, building materials sourced locally to reduce transportation requirements; materials that require less processing; and those that retain heat.
“These factors can make a significant contribution towards reducing global warming and climate change.”
Earth building is an environmentally sustainable form of construction which has been around for about 10,000 years and involves the use of soil as a primary construction material. It can be considered a stand-alone natural building philosophy, or as a set of techniques that complement more conventional modern building practices to add character, durability and environmental sustainability.
Radiata pine trees are one renewable resource grown in the South Island, easily accessible for New Zealand construction projects.
“Locally-sourced materials should be prioritised – not only are they better for the environment, but they are also better for the local economy and financial sustainability,” notes Dr Samarasinghe.
The New Zealand Building Code stipulates standards for weather tightness and details thermal efficiency regulations that must be met. This is another way the construction industry can contribute to sustainability in such a way that benefits our planet.
“New Zealand is a colder country, and a lot of energy is required to heat our homes and buildings in winter to ensure health and safety and comfort,” says Dr Samarasinghe. He advocates for considering the use of environmentally friendlier materials that retain heat wherever possible, such as concrete instead of steel.
Another opportunity lies in the old adage, ‘reduce, reuse, recycle’ – particularly as it relates to a building’s lifecycle. What if, once a building lifecycle is complete, you could repurpose material that would go on to have a positive impact?
“This requires clever design thinking at the outset to optimise opportunity,” says Dr Samarasinghe. “For example, concrete is a highly processed material, but it can be crushed and used for other construction projects, such as road construction, and even used as aggregates to make new buildings.”
Dr Samarasinghe says Māori models of wellbeing always centre people – as evidenced by the whakatauki, or proverb, ‘He aha te mea nui o te ao? He tangata, he tangata, he tangata/What is the most important thing in the world? It is people, it is people, it is people. He believes the construction industry should do the same.
One way to prioritise people is to provide an equal opportunity workplace, a requirement that is the responsibility of every construction firm in the country. Irrespective of a person’s ethnicity, nationality, sexuality or gender, workplaces are expected to welcome and support diversity.
Because construction is such a high demand industry, many overseas workers have historically been brought into New Zealand for their skills, making for a multi-cultural work environment.
“In these workplaces, it is important to foster understanding and respect of different cultures,” he says. “For example, Muslim workers may be fasting at times, and it would be best for them not to be assigned heavy lifting duties during that time. Daily toolbox meeting can be a great opportunity to bring these to light.”
The Government is clear on the requirement to ensure every workplace provides equal opportunities to Māori and Pasifika workers, and gender equality for women in construction. In an industry is made up mainly of men, there are some quarters that maintain an outdated mindset about women in construction.
“Offering more opportunity for everyone will bring many benefits, including a positive impact on the long-standing skills shortage problem,” says Dr Samarasinghe.
It is also critical to ensure staff have sustainable workloads, to enable optimum productivity.
“Every person comes with different sets of skills or abilities. Humans are not machines – we are people with families and our own lives outside of work. Connection is key – construction industry leaders should make sure they know what is going on with their staff.”
People must also be protected by adequate health and safety provision in the workplace, particularly in construction which is known to be a hazardous environment. Compliance with the Health and Safety Act of 2015 is essential, and appropriate equipment and education must be provided.
All of these people-centred accommodations make for a healthy work environment – one where staff feel supported, respected and part of a positive culture.
This pillar is a special feature of the New Zealand model of sustainability. It relates to considering the purpose of a building – be it residential or commercial – and how it will be used.
This means reflecting on maintenance requirements, health, safety, comfort, energy consumption, weather tightness, thermal efficiency, insulation, and so on. In other words, the value to the people living in or using the building.
“For example, a shopping complex has a commercial purpose,” explains Dr Samarasinghe. “Considerations for its construction include open space utilisation, circulation, movement both horizontally and vertically, natural light and energy consumption mitigation.”
He says in an ideal project, every factor should be aligned with the purpose of the building – from cost and materials to operation and maintenance requirements.
“Sustainable construction still needs to be profitable, or no-one will invest in it,” says Dr Samarasinghe. “The simple equation is that profit equals revenue minus cost, so minimising cost is very important.”
He says half of a project cost usually relates to materials, and the other half to labour costs. As a result, the choice of materials plays a very important role in profit margin.
As mentioned earlier, locally-sourced, locally-manufactured materials have a lower cost, because it is expensive to transport materials to New Zealand from elsewhere in the world. This is unnecessary, unsustainable material cost.
“Another issue is the lack of standardisation in New Zealand buildings, and this significantly increases cost,” says Dr Samarasinghe. “One solution is to introduce more standardisation, such as those seen in affordable housing villages. This can reduce the need for specific workmanship, labour and materials, and will increase profit values.”
Construction innovation can play a role, too. Prefabrication is one way to reduce the need for labour on site to increase profit – convenient in a skills shortage. Centralised BIM systems can keep a project lean, by cutting down on unnecessary delays and increasing profit.
“Lifecycle cost should also be considered. Properly insulated buildings with double glazing will reduce the lifecycle cost for home or building owners,” says Dr Samarasinghe.
He says designers have a lot of responsibility for thinking about these matters at an early stage – including ways in which commercial buildings can be used to optimise profit.
“Multifunctional design is another option – if it’s an art gallery, library or mall, can it be used for other purposes at different times of the day or year? Conferences or events, for example.”
The Sustainable Business Network is a great resource for learning more about incorporating sustainable practice into construction and other industry within New Zealand.