According to the long-term strategy for the renovation of Estonian buildings, around 5,300 apartment buildings and 40,000 private houses will fall out of use over the next 30 years as the population declines and buildings depreciate*. A large amount of demolition waste is therefore being generated, and the possibility of their partial recovery needs to be explored. Researchers at the Tartu College of Tallinn University of Technology are working on this issue.
This is not just a problem for peripheral regions, but for most of Estonia’s cities, diminishing small towns and villages. Apart from Tallinn and Saue, all the other cities are losing population at a faster or slower pace.
According to Mihkel Kiviste, Professor at the Tartu College of School of Engineering of TalTech, the recovery rate of construction and demolition waste in Estonia has been quite high in recent years – a study conducted in 2018 showed that as much as 84 percent of it was reused. It is true that, unfortunately, it was and is mainly low-value recovery (e.g. construction waste used as soil fillers) rather than recycling.
What solutions are TalTech researchers offering?
‘In order to ensure long-term climate goals, a reduction in the carbon footprint of the built environment and sustainable development, it is necessary to move from the current linear economic model towards a circular economy,’ says Kiviste. ‘Therefore, instead of the traditional demolition of buildings and the disposing or using for filling of construction and demolition waste, the recycling of building elements and materials should also be considered. In this way, we can reduce the need for primary raw materials and the amount of construction and demolition waste that needs to be landfilled.’
According to Kiviste, Estonia’s current practice in demolishing buildings is to put out a call for tenders, and the lowest bidder starts demolishing. ‘There is not much left intact in the process, but a big pile of construction debris,’ says Kiviste. ‘However, demolishing in a new way would be like building upside down – the building would be selectively dismantled, starting with the roof. Of course, this is more expensive than simply bulldozing the building. However, this is the only way to obtain the building materials that can be recovered.’
*Read the article in Delfi Ärileht.