25.03.2019The construction sector accounts for substantial emissions, and the level of reuse in the industry is low. But why is that so, and how can we turn it around? These were the main issues discussed on a lunch seminary on recycling in a circular perspective at COWI’s head office in Oslo, Norway.
Buildings need to be more sustainable – and preferably environmentally certified in one way or another. What is more, around 30 per cent of all waste in the EU is pure building waste. This is one of the biggest paradoxes and challenges faced by the construction industry today, said Erik Rigstad, development manager for buildings at COWI, at a recent lunch seminary on recycling in a circular perspective at COWI’s head office in Oslo.
“At COWI, we run into problems at the intersection between recycling of materials and sustainable construction, such as BREEAM and low-emission buildings. We are aware that there are unnecessarily large emissions, even from BREEAM buildings, because many of these buildings are also new and the raw materials are being used for the first time. The industry is good at documenting the choices we make and at certification, but we can go further when it comes to our choices of materials,” said Rigstad.
Tore Methlie Hagen, a civil engineer within construction and working in the environment division at COWI, gave a presentation on the circular economy in the construction sector. Based on a report produced by COWI for the Nordic Council of Ministers, Methlie Hagen went into the major challenges to be addressed if the construction industry is to be more circular.
“In the report we identified some of the biggest barriers faced by the Nordic countries today, according to interviews with 16 stakeholder groups across these countries. Among the findings was that there is no cooperation across supply chains. And buildings have a long life. So many of the buildings we are now demolishing have already been around for 70 or 80 years. This raises issues in our circular efforts both because of hazardous substances and because the quality of materials does not meet present-day requirements. And the buildings were not suitable for dismantling and reuse either,” explained Methlie Hagen.
“All of this complicates the work of recycling. One of the most important lessons we have learnt from history is that we need to put up buildings that are easier to dismantle and reuse.”
Then comes one of the biggest drivers behind the whole thing: cost.
“We have significant transaction issues that pose major risks to the projects. We are dependent on solving the cost part – in order to increase the amount of recycling, the players all along the supply chain need to have financial incentives to achieve dynamic effects, which calls for public investment and support.”
His experience from the industry is that the level of recycling has been highest and most stable for the waste types that are most profitable to recover.
“Metals, for example, have always been quite profitable, but you can’t say the same of paper and concrete. Landfill has also been historically very cheap. The ‘final treatment charge’ which was introduced in the late 1990s was a major financial incentive to promote recycling and reuse. These are the effects we now need to develop further,” said Methlie Hagen.
He also observed that the waste regulations can be a barrier in themselves to recycling and circular economy in the construction sector. The rules are inflexible and mean that large parts of the construction waste must be treated as general waste and cannot simply be recycled into new building materials.
This is particularly true where old buildings are demolished to be replaced with new and sustainable structures – where the old buildings do not satisfy current standards for certification or would be hard to upgrade to the latest energy requirements, for example.
“In these cases, the waste regulations can be a barrier. Unclear rules for reusing concrete, for example, can also limit the actual amount of recycling. The waste regulations as they stand today can place restrictions on a circular economy, so we need the current rules to be tidied up,” said Methlie Hagen.