6 May 2011 – Special Report: Carbon tax or not we are moving inexorably towards a world where carbon emissions will be factored into goods and services. It’s either that or head lemming-like towards catastrophic warming of the planet. That’s what building materials manufacturers as well as some leading property developers, engineering firms and construction companies are counting on and they are working hard behind the scenes to develop more sustainable, less carbon intensive materials.
So what is emerging from the R&D labs? Quite a lot as it turns out, particularly in timber where some new composite materials claim to be achieving a significant reduction in energy use and carbon emissions.
At a recent gathering at Sydney’s temporary pop-up sustainable restaurant, Greenhouse by Joost sponsored by engineering consultants, Arup, there was much talk about building materials (see our story on this). The word was that materials had lagged behind in their sustainable credentials and were about to undergo a revolution.
Arup is at the forefront of the push for innovation, along with researchers at the CSIRO, university research departments and several leading development and construction companies, such as Grocon and Lend Lease.
We also reported recently on the work being done on life cycle analysis of materials and products. This analysis of a material’s impact from its very beginning to end of its life is not only changing the way building materials are made but also the way they are transported, installed and used. Also emerging are innovative ways of combining different materials to maximise their various properties.
No such thing as a bad material says LCA expert
Nigel Howard, managing director of life cycle analysis consultancy Edge Environment, told The Fifth Estate that while it is tempting to ask which material is the most sustainable, it is misguided.
“People do ask whether this material is more sustainable than this one but they are asking the wrong question,” Howard says. “They are pushing the wrong barrow – there is no such thing as a good or bad material – the answer lies in a combination of materials.”
Howard cited the example of Polyisocyanurate foam, a type of polyurethane used for insulation, as an example of how the good qualities of a material can outweigh its bad effects.
“This is a material that has extremely high environmental impacts but it is also the best insulator. Suppose you have a hollow door that you need to insulate – the amount of energy you save by using this foam outweighs its negative impacts. It really is about the combination of materials and the trade-off,” Howard said.
Many researchers are looking at new combinations of materials and also replacing traditional materials with new. Some exciting work is being done in this area with new timber products such as cross laminated timber panels, which involve gluing layers of wood together to form large 12 x 2.4 metres panels, similar in mass to concrete but with the ability to store carbon. With laminated strand lumber and laminated veneer lumber even larger panels, around 19.5 x 2.4 metres, can be constructed. These are typically used as beams in construction and can replace steel.
At the Green Cities conference earlier this year Michael Green, principal of Canadian architectural firm mgb Architecture+Design, argued strongly for timber as a superior alternative to concrete and steel (see our story on this). He said that timber was the only building material that would simultaneously reduce carbon emissions and remove carbon from the system, something that is essential to reduce global carbon.
Timber’s time has come say researchers and engineers
Haico Schepers, Arup principal, says there are exciting things happening with timber. And because it has been largely neglected as a material in Australian commercial construction, wider use of timber has the potential for dramatic savings in carbon footprint of buildings, in some cases close to 50 per cent.
Arup is currently quantifying the carbon footprint of both timber and concrete used in the same applications within a particular building. The results are impressive.
“We’re trying to quantify what the environmental benefits are of using timber instead of a very efficient concrete. This involves taking into account the different types of treatment needed for timber to prevent moisture traps and also the impact of things like glues.
“What we’ve found is that timber can reduce the embodied carbon by 20 per cent but if you take into account timber’s ability to sequester carbon it is almost a 50 per cent reduction. To put that into context, this is close to five years of a typical base building’s operation,” says Schepers.
Arup is working with researchers in both Australia and New Zealand, supporting the Structural Timber Innovation Company, or STIC, a joint research program by three universities – University of Technology, Sydney, Canterbury Christ Church University in Christchurch and the University of Auckland.
The Arup team is also working with leading developers such as Grocon and Lend Lease, both of which are keen to be the first to build a high rise building in timber in Australia. Grocon has plans to build a residential tower on the old Carlton United Brewery in Melbourne, while Lend Lease is looking at timber for the Barangaroo development.
Arup principal Richard Hough has been working closely with timber researchers and he believes its time has come.
“Arup is keen to be involved in the uptake of timber – its time has come particularly as it is not much used as yet in the [Australian] construction industry. There is a lot of interest in using it in multi-storey residential and commercial buildings,” says Hough.
The advantages of timber are many, according to Hough. These include:
- speed of construction
- convenience in urban centres because of low noise and simplicity of construction techniques
- it is lightweight so is suitable for sites with poor foundation materials
- it has strong sustainability credentials including ability to sequester carbon
With carbon accounting on its way, this last factor is increasingly important. One project Arup is busy with involves the use of cross laminated timber panels in 145 apartments in western Sydney.
“The project involves three seven storey blocks of apartments and it could be the first cross laminated building in Australia, if accepted. CLT is becoming more popular in Europe – it was used in London, in Hackney, in what is amongst the world’s tallest timber building. (see our story on this )
“One of the key drivers for that building was that the borough accepted the emissions savings of timber as a sufficient offset for the regulated requirement for onsite renewable energy,” Hough said.
This sort of regulatory flexibility is powerful in kick starting new technology says Hough and Arup are currently talking to regulators, including the Building Codes of Australia, about fire and acoustics requirements in the BCA code that restrict the use of timber in buildings above three storeys, something that can be overcome but that does inhibit wider use of timber.
“At about three storeys one needs a fire engineering approach to justify timber use. We’re having discussions with the authorities about this and I do think they’re very aware of the uptake of timber elsewhere,” Hough said.
In Nelson, New Zealand a four storey timber building is due for completion this year. Hough believes it won’t be long before we see widespread use of timber in multi-storey buildings in Australia.
“If we are living in an economy based on carbon accounting I can imagine every three or four storey block of apartments in Sydney being made of timber.”
Keith Crews, professor of structural engineering and Sydney project leader at the University of Technology Sydney for the Structural Timber Innovation Company, told The Fifth Estate that wider uptake of timber for commercial buildings would require better training of engineers in the use of timber.
“Timber has a footprint in commercial and industrial buildings overseas but not in Australia. Here we are very much influenced by the English mindset based on masonry. Architects and engineers have been educated in the use of concrete in design and don’t have the design tools to deal with timber. Unfortunately there is widespread ignorance of the material,” says Crews.
Since 1993 Crews has been working on changing that. He says that if he’d been talking to developers about using timber 10 years ago they would have thought he was crazy. Things have moved on.
Now there is recognition of timber’s advantages – it is lightweight compared to concrete and steel but has similar compressive qualities to concrete, in some cases higher. It is also superior for longer spanning structures such as roofs, says Crews.
All materials are subject to wear and tear, steel being vulnerable to corrosion, concrete to concrete cancer and timber to moisture traps, although the latter could mostly be overcome with modern construction techniques and appropriate design.
UTS is working on the development of long-span timber flooring systems, in particular timber concrete composites. This involves combining timber with concrete to get a more optimal solution for flooring systems, which the team believes could be a structurally-viable solution for large commercial complexes.
The key to successful research, says Crews, is constructability and cost effectiveness or exciting new technologies will never see the light of day.
“This has been developed on paper and is now being manufactured in Melbourne. It lends itself to hollow floor systems and the physical testing will start soon. We’ve got keep costs in mind – installation cost is important and with this system you can save money on cartage and foundation costs,” says Crews.
Another crucial factor for any new material is to educate quantity surveyors to learn about costing them and not just focusing on traditional systems.
Crews acknowledges that timber will not be viable as a widespread building option without truly sustainable forestry practices. In the short term the market is depending on timber from New Zealand forests but in the long term planting timber in appropriate locations would be essential.
“Some large scale greenhouse gas producers are getting offsets by planting plantations but we can’t allow mass destruction of our hardwood forests. Some farmland is marginal and unproductive – that could be an option.
“We also need to look at the way land is currently used. In this country we have huge interests in coal and iron ore. We believe we could effectively utilise some of this land.
Even if timber were to take 10 to 15 per cent of the current markets for steel and concrete, particularly in three to four storey buildings, it would make an enormous difference, says Crews.
“It would put a renewable product in buildings that also reduces greenhouse gas emissions and it would change the way we think about buildings.”
But in the end it is not about replacing one material with another. The most effective buildings, says Crews, utilise a combination of materials, maximising their particular strengths for a given function.
Reducing the impact of existing materials
When the Green Building Council of Australia changed its approach to rating building materials a year or so ago, there were rumblings in the industry that it was caving in to pressure from manufacturers. After all every manufacturer has got commercial skin in the game and influencing the key green building body is a powerful move.
The change in approach meant the GBCA began working more closely with materials producers and seemingly lowered the bar for some of its sustainability criteria. As we reported at the time, the GBCA argued that its new criteria for the four key materials – steel, concrete, timber and PVC – would not make things easier for manufacturers, but instead would encourage and reward industry innovation by focusing on best practice for each sector. (see our previous story).
PVC, a contentious material
One of the most contentious decisions was to include PVC in Green Star, where previously the GBCA had discouraged its use by rewarding points for use of alternative materials. Banned in some areas of Europe, key concerns with PVC centre on the manufacture of chlorine and the emissions of dioxins.
See what technical experts at the New Zealand Eco Labelling Trust say about PVC
The GBCA argues it is encouraging minimisation or removal of lead, chlorine and dioxins from manufacturing of PVC by only accepting material manufactured to best practice guidelines.
In a recent interview with The Fifth Estate Robin Mellon, GBCA director, stood by the GBCA’s decision to go down the best practice route, saying he believes the new approach is encouraging change.
“This approach [best practice] fits best with Green Star and also with Australian industry. All global markets are very different and their approach to materials differs – PVC for example is treated very differently in the UK and the US.
“Of course this raises the question of how to define best practice. Australia is pretty much world leader in defining best practice. It is about doing things well rather than less badly and we need to take the market along. It is an incremental thing but things are changing for the better – I really think they are,” says Mellon.
PVC industry argues it has a role in reducing carbon emissions.
Not surprisingly the PVC industry is also convinced the move is the right one.
Sophi MacMillan chief executive of the Vinyl Council of Australia, told The Fifth Estate the PVC industry has an important role to play in sustainable buildings because of the product’s relative low embodied carbon and its strong thermal properties.
“PVC is lightweight and has extremely good thermal qualities so we will see it much more widely used for lightweight cool roofs and window frames in addition to traditional use in pipes, conduits, cable insulation and flooring,” says MacMillan.
One of the main reasons the GBCA changed its policy on PVC was the stewardship program introduced by the industry in 2002. According to Macmillan this program has been highly effective in lifting standards in resin manufacturing and use of additives, reducing carbon emissions in processing and improving recycling practices
The manufacture of PVC is highly regulated through the Environmental Protections Agency but in addition, says MacMillan, the Australian industry’s voluntary standards are the tightest in the world. She says 70 per cent of the market, including manufacturers and importers of PVC products are signatories to the stewardship program. Control of resin manufacturing is also very stringent, says MacMillan.
One of the key areas for improvement has been the phasing out of lead stabilisers from PVC products by the end of 2010. PVC pipe and cabling manufacturers completed this by 2008 and the Vinyl Council is now getting data to confirm the rest of the industry has completed the phase-out.
Much work has also been done on life cycle assessment, with resin manufacturers introducing water recycling plants and focusing on energy efficiency, says MacMillan.
A key innovation in the industry has been the development of a permanent formwork system for walls that lowers the percentage of concrete and steel needed in construction. Created and developed in Australia by an engineering firm the Dincel Construction System is certified by the University of New South Wales and the CSIRO. Once the formwork is in place it is filled with concrete.
“The system offers significant advantages because it is durable, lightweight and its structure means walls have less embodied energy than traditional cement walls, using less concrete and steel,” says MacMillan.
An emerging area for the PVC and polymer industry generally is the development of bio-based additives based on plants and food oils. These could replace traditional chemical additives.
“Most polymers are hydrocarbon based. PVC has an advantage here because only 40 per cent of its content is derived from oil and the rest is from salt, which is where the chlorine comes from. For other polymers such as polyethylene and polypropylene the oil content is higher. This means PVC has a lower embodied energy. If the industry can replace the ethylene with bio feeds then this will lower it even further and we are seeing a lot of research in the area overseas.
“But while it is an emerging area, growing more plants for fuel does raise questions about land issues and bio-diversity, “says MacMillan.
A major focus of the PVC industry right now is recycling. Technically PVC is very easily recyclable, says MacMillan – it is simply put in a chipper and broken down and for re-use. But there are major barriers to efficient recycling in terms of infrastructure, regulations and logistics.
“We have a recycling summit in May where we’ll be getting all stakeholders together including manufacturers, product designers through to builders and waste contractors. We need to map out a pathway to make PVC recycling easier. It requires new technologies, systems and infrastructure to make it work more effectively,” says MacMillan.
Manufacturers of PVC are demanding more recycled material so that they can reduce their use of virgin resin and compounds but they cannot get nearly enough.
“There are genuine dilemmas – for example on a residential site you can’t have a skip for each type of material so it all goes in one. Recyclers focus on dense materials such as steel and concrete as it is difficult for them to economically recycle the lightweight materials such as PVC, which has big volume but low mass.
“If we can make recycling more efficient by improving the systems we can reduce carbon emissions in the industry significantly,” says MacMillan.
Centre for Sustainable Materials Research and Technology
At the Centre for Sustainable Materials Research and Technology (SMaRT@UNSW) at the University of NSW several projects are focused on improving the sustainability of existing materials such as concrete, steel and aluminium. Others are developing new smart materials.
SMaRT brings together researchers from the Faculties of Science, Engineering, Built Environment and UNSW@ADFA to work with industry on the development of innovative, sustainable materials and manufacturing processes.
One SMaRT project involves the development of a lightweight, geopolymer concrete that provides high compressive and tensile strengths. Geopolymer concrete does not contain ordinary Portland cement (OPC), the main ingredient in concrete. The most widely produced man made material on earth Portland cement is a major contributor to GHG emissions. Inorganic polymer concrete utilises ‘fly ash’, one of the most abundant industrial by-products on earth, as a substitute for Portland cement.
In addition to its potential to reduce CO2 emissions geopolymer concrete is also more durable than ordinary concrete and its use of fly ash eliminates the need for the by-product’s disposal.
Another SMaRT project is exploring the use of waste plastics as a carbon source for the aluminium industry, helping to reduce GHG emissions and reliance on landfills for waste disposal. Researchers at SMaRT have already developed bricks and building aggregate that can be made entirely from fly ash.
CSIRO aims for commercial follow-through
At the CSIRO, senior research scientist Greg Foliente has been involved in a broad range of research projects involving building materials. He believes there is still a large gap between creating exciting materials in R&D departments and getting them to market.
“At the CSIRO we think through the commercial process and try to pass it on so that there is follow through. But the amount of money required to take something from pilot through to commercialization and then to market it is enormous. The second challenge is the nature of industry – it is hard to move and change things because it is risky.
“There is a lot of exciting stuff happening in the lab but I don’t see it translated at the same pace in industry,” says Foliente.
While it is a worldwide trend there are a few exceptions – Japan, China and some parts of the United States. In company terms General Electric is a leader in innovation, willing to take on risk and to explore new technologies, including in renewable energy.
“These things are not short term investments and to be a leader and an innovator requires long term vision,” says Foliente.
Some of the most exciting technologies Foliente is seeing emerging are printable solar panels that are a fraction of the cost of earlier technology and that can be printed on mass and used in just about any surface. If a company like GE picked it up, Foliente is confident it could be in the market in one or two years. If a smaller company picks it up it’s anyone’s guess.
On the building materials side of things, much of the current research is focusing on reducing the adverse effects of production and disposal. A key part of tracking all aspects of a material is the use of micro-sensing technologies or radio frequency IDs. While this is not new technology and has been around in grocery scanning for decades, it is being used in new ways to tag and trace components of building materials. This means the history, current use and future destination of a material can be traced.
“One wall panel can have 10 parts so if each is traceable this encourages product stewardship and allows a full environmental footprint of a product or material. We can see how long it lasts and where it goes,” says Foliente.
Such technology can be used for infrastructure, for example to monitor a critical component in a bridge. If used in conjunction with smart materials that can self-repair the benefits are immense. Apart from the obvious safety benefits, the information will lead to better production techniques and lower costs.