Contact person
Johan M Bergström
Projektledare
Contact Johan M
How we can build new from old
Municipalities are attempting to achieve ambitious climate goals, but must also meet the increasing need for new housing and premises. The construction sector wants to become part of a circular economy – but must first and foremost comply with strict building codes and material requirements. These are not simple equations, but reuse is part of the solution.
The construction sector is undergoing a major environmental transformation. Within a few years, by 2027 at the latest, new legislation is expected to regulate emission requirements for new buildings. This will see a shift from declaring the climate impact of buildings, as is done now, to minimising the actual climate impact.
New legislation rewards reuse
“This will reward reused products,” says Johan Bergström, Project Manager at RISE. “In practice, we will go from the legislation being an obstacle to it pushing for more reuse.”
The EU’s different requirements within the new taxonomy and regulations on construction production and ecodesign will mean that it will be profitable to reuse as much as possible. A large proportion of all new buildings are also environmentally certified, and these systems have either included reuse as part of their requirements or are in the process of doing so.
Johan Bergström has a background in the construction sector and leads an initiative at RISE to coordinate the work that will increase the circular flows of building materials:
“There is a great deal of interest in society among builders, municipalities, and architects. A whole new industry is emerging. Where there used to be waste contractors and demolition companies, there are now also contractors who explore possibilities to find value in the materials in a building that needs to be demolished or condemned because they want to build something new on the site.”
It really is possible to use a lot of the old material
Certification of reused materials
Although there is considerable interest and willingness, there are obstacles that must be overcome. Bergström points out that pre-used building materials do not necessarily have poorer quality, but that it is more difficult to know exactly what you have to work with. If a developer buys newly manufactured material, they know what requirements they can set, where the responsibility lies if the requirements are not met, and, ultimately, what the material can be used for.
“That’s why we’re working to develop quality criteria, with the possibility of certifying and labelling reused materials. We should be able to answer what it means for requirements regarding things like acoustics, moisture, and strength when the material has been in a certain environment for a certain time. Knowing that the building material can be used directly or whether it needs to be restored creates greater security for the clients, and thus the procurers can also more easily demand a certain proportion of reused material in a new building.”
RISE is working with Fabege, NCC, Vasakronan and others in the Återhus – Att bygga hus av hus (Eng: Re-house – Building Houses from Houses) project. In the Stockholm district of Haga Norra, almost 70% of a new building has been built from materials from an old vehicle workshop and car showroom. Even the old joists could be moved to the new building.
“It really is possible to use a lot of the old material. Based on inventories, decisions can be made – before a new building is designed – about which materials can be dismantled and reused. Work is underway in various development projects to determine how different building materials with different functional requirements can be reused. For example, how can the fire rating of old fire safety doors be retained or how can the porcelain from old toilet seats be used while replacing the flushing mechanism?”
Local initiatives create new markets for reused materials
Bergström points out that there are now many local initiatives to create markets for reused materials. At the same time, tools are needed that create a better national overview, and tools used for digitalisation and traceability can help. One vision would be a single, national database to search for products, which could then be entered directly into the digital models at the drawing stage.
“Since I started working at RISE in early 2022, I’ve realised that different fields need to work together to make reuse possible,” says Bergström. “This includes, for example, architecture, physical planning, and construction processes, as well as knowledge of moisture and microbiology, life-cycle assessments, and, of course, quality assurance and certification. RISE is involved in all these fields, and I’m convinced that a lot will happen in the coming years. In addition to better planning, better use of existing buildings and, of course, renovation and material recycling, reuse will be a way to reduce both resource use and climate impact from the construction sector.”
MAJOR CLIMATE IMPACT FROM THE CONSTRUCTION SECTOR
According to the National Board of Housing, Building and Planning, a fifth of Sweden’s domestic climate impact comes from the construction sector. And the sector’s climate impact increases further when adding its emissions from material imports. The construction sector also accounts for a third of all waste produced in Sweden. Globally, about 40 percent of the world’s consumption of natural stone, sand, and gravel stems from the construction sector. Using resources efficiently and achieving circular flows are identified as central to the industry’s roadmap to net zero greenhouse gas emissions by 2045.
REUSE PROCESS REQUIRES MORE STEPS
To reuse the material in existing buildings – and see the potential during a demolition – work is required in several steps. The following is a brief methodology of the reuse process:
- Environmental risks. A building to be demolished must be environmentally inventoried so that it is clear whether any environmentally hazardous substances are present in the building and the materials.
- Inventory. The material to be reused from a building is inventoried at a detailed level, so that its status and condition can be determined prior to planning.
- Sorting. Inventory must be done with knowledge of how, and if, the material will be reused. Likewise, if the material will be sold, stored, or used directly in another building.
- Preparation. The material must be carefully dismantled and may need to be restored before it is reused.
- Transport. The material must be transported to the new building or to a warehouse pending use.
To achieve circular flows, knowledge is required in procurement, design, inventory, and quality assessment, and functional traceability of the material must be possible so that, during a project, it can be determined whether the material sought after is available elsewhere in the country.
