A regular series from Goodman Property examining environmental sustainability and how New Zealand business is working to get us there.
Today: The effect building construction has on the environment.
The problem: In New Zealand, buildings are responsible for about 20 per cent of all carbon emissions. The expert: Sam Archer and Andy Eakin. A sustainability consultant who worked for 18 years as a structural engineer in the construction industry, Archer is the director of Market Transformation at the New Zealand Green Building Council (NZGBC) where he runs Holistic Sustainability Assessment Tools, Green Star, Home Star and Neighbours NZ. Eakin is CFO of Goodman Property which is working to reverse the rate of carbon emissions from buildings. An investor and developer of industrial real estate, they are targeting a five-star green rating for all new developments.
Construction industry urged to go green to counter its 'profound' effect on the environment.
- New Zealand's annual $30 billion spend on the construction of houses and commercial buildings has a profound effect on the environment. The average-sized house will emit 63 tonnes of carbon dioxide over its lifetime; Archer says buildings account for about 20 per cent of the country's carbon emissions.
- "Roughly 50 per cent of waste that goes to landfill comes from the construction sector," he says.
- "The construction industry's record on sustainability lags 10 years behind Australia and maybe 20 years behind the UK."
Building construction damages the environment in lots of different ways, the main culprit being carbon emissions, Archer says: "Roughly 20 per cent of our emissions is from the built environment – 10 per cent of which comes from the way we operate our buildings (the gas and electricity used in them) and the other 10 per cent from the construction materials that go into making those buildings in the first place." .
Of these materials – which he refers to as "upfront emissions" – typically four or five (like cement, steel, aluminium, glass and timber) make up 80 or 90 per cent of that impact.
But, says Archer, the way construction material is extracted from the ground, the timber cut down, quarrying and rainwater run-off from buildings also have significant impact.
"When you take a piece of green land and put a whole load of concrete on it, suddenly the rain runs off much more quickly and takes pollutants with it into local streams and erodes their banks."
Waste is also a huge problem. "Amazingly (this is) between four and five tonnes of materials from every single house built in New Zealand and the reason it is such a bad thing is because it represents materials that had carbon from the construction stage.
"You're throwing away carbon and wasting materials – so it's not only wasted carbon emissions but it's also wasted money," Archer says.
He says it's well known that our industrial standards and the building code are some of the lowest in the OECD: "We've got a really long legacy of very cold, damp housing - no central heating, very little insulation, very, very little double glazing. We've got a long way to go."
Faced with these problems, Archer says the NZGBC has a goal of making all buildings in Aotearoa green and sustainable. The council has introduced the Green Star sustainability rating system for building standards, campaigned for regulatory reform, inspired the building of sustainable buildings and provided education and training throughout the country.
Although slow, Archer believes headway is being made. For example, in the last six to seven years, the New Zealand cement industry has reduced emissions by about 30 per cent; most of the big suppliers of products and materials are doing lots of carbon footprinting and thinking about what emissions are associated with their products.
The NZGBC is doing work around waste. "If you rate your building with us, typically we're asking you to reduce the amount that goes to landfill by 80 per cent – and most of our projects are achieving that.
"We could be doing more off-site construction," he says. "If you build modular components, or even the whole house in a factory, very often it results in much less waste."
Archer also believes New Zealand could be building smaller houses because the bigger the house, the more materials are being used and the harder it is to heat. They should be well insulated and the hot water, heating and lighting systems should be as low energy as possible.
"I think it's perfectly possible that in 20 years key industries like cement, steel, aluminium, timber and glass will have completely re-tooled their factories to make products in a low carbon, if not zero carbon way.
"I hope the design industry will design a building with very low (environmental) impact and think about how a building can be optimised to use less material, energy and create less waste."
Goodman CFO Andy Eakin says the company is trying to take a lead in trialling some of the new (sustainability) techniques and drawing on expertise from elsewhere in the world.
"Concrete is probably the biggest thing for us. We've been using a lower carbon version in our construction and 15 per cent fly ash as a cement replacement," he says.
"On the steel side of things, the nirvana would be a zero carbon steel but it's not available in New Zealand, so we're looking at timber construction to see if we can replace some of the steel. Timber is obviously a very good solution, completely renewable and much lower carbon in terms of its footprint."
Eakin says Goodman is installing solar panels on new and existing buildings and looking at rainwater harvesting as a standard feature on its new buildings.
The water collected can be used for the toilets and things like washing trucks, the building itself and for irrigation. "We like to plant out and make the industrial buildings look pretty nice as you drive past them. This (harvesting) reduces demand on the city supply and, as we know in Auckland, anything we can do to lower this demand is a good thing.
"One of the standard features we put into our new buildings is LED lighting which has a very low energy draw," he says. "We've got a programme to put replacement LED lights in existing buildings that don't have them which significantly lowers energy demand and saves money for the customers who occupy the building."
Eakin says all Goodman's new construction contracts require detailed waste audits so the company knows what waste is being generated and where it goes to.
In cases where it is demolishing buildings for re-development steel is being recycled. Concrete is crushed on site and re-used as aggregate which, he says, means not only is it a saving in taking stuff to landfill and the truck movements to get it there, it means you're not having to quarry new aggregates.
Footprint: Business Sustainability is a new podcast series from Newstalk ZB and Goodman Property. Episode 4: Construction is out now.