Cinderela project is testing the way Circular Economy can be implemented in wastewater management

In Europe, the construction sector accounts for one-third of all EU waste, one-third of all water consumed, making up for the largest share of the total EU final energy consumption 

The reduction of the construction sector’s environmental impact 

In Europe, the construction sector generates about nine percent of the Gross Domestic Product (GDP) and employs eighteen million people. It accounts for one-third of all EU waste, one-third of all water consumed; making up for the largest share of the total EU final energy consumption (forty percent). It produces about thirty-five percent of all greenhouse emissions. Globally, according to OECD estimates, the construction sector is expected to double between 2017 and 2060.

So will its use of materials, leading to about eighty-four Gt of construction materials used per year in 2060. With the Climate Crisis and urbanization approaching, the construction sector faces a challenge. How to make the reduction of its environmental impact go hand in hand with rational use of resources and economic growth? The UN data shows that fit-five percent of the human population lives in metropolitan areas. This is expected to rise to sixty-eight percent by 2050. Projections show that urbanization joined with the general growth of the world population. This could add another 2.5 billion individuals to urban areas by 2050. 

Urban waste to produce secondary raw materials

In line with these numbers, these zones are expanding. Most of the construction activities occur in urban and peri-urban areas. Producing large quantities of different types of waste currently unused. For example the ones generated by the construction sector, municipal services, and other industries. For instance, this urban waste could be employed to produce secondary raw materials; whose employment in construction works would maximize the value of recovered materials.

It would reduce the demand for virgin materials and the production of waste; creating an opportunity for circular business for construction companies. Said businesses face difficulties when trying to implement a circular approach that involves using secondary raw materials (SRM). This is because they often lack the necessary business practices, technologies, and specialized knowledge. Other barriers are the abundance of low-priced virgin materials in some European regions. This is to say poor trust, low acceptance concerning the use of SRM-based construction products, the lack of appropriate legislation, and established administrative procedures. 

AMS Institute and Delft University of technology partnership with Cinderela

Cinderela is testing the implementation of Circular Economy in wastewater management; in collaboration with the AMS Institute and Delft University of technology. They opened a laboratory, housed in a refurbished shipping container, with two toilet bowls, a bioreactor, and a rotary evaporator. Therefore, municipal sludge formed after residual wastewater treatment, can be a source of secondary raw materials for construction with appropriate processing. In addition, with the current wastewater management practices, many components that are necessary for our food-cycle end up in municipal sludge. At this demonstration plant, located at the Marineterrein Amsterdam Living Lab (MALL), Nitrogen and Phosphorus are recovered from urine before ending up in municipal wastewater. The entire waste is treated by removing micropollutants, pathogens, and foul odor, and a liquid high-grade organic fertilizer is created. 

CinderCEBM: Cinderela business model

Cinderela develops and demonstrates a circular economy business model dedicated to the urban construction sector called CinderCEBM. This is to face these issues and aid the construction companies; willing to exploit urban waste untapped potential. Cinderela also created the CinderOSS to make the use of SRM-based construction products resulting from CinderCEBM. More straightforward for the target users, like companies and local administrations. This One-Stop-Shop service provides evidence-based knowledge on the production and use of circular construction materials in construction works. News and updates on the research and development of existing and upcoming recycling and construction technologies. On top of that, they offer a platform that fosters collaborations between potential colleagues, clients, and other likely partners. 

Surveying the waste-to-resource potential: Cinderela methodology

Information is key to developing circular business models in construction. Entrepreneurs need reliable data. Not only on the sources of SRM but also on the overall business environment in which the business model is. To operate and the benefits and limitations they may experience. To provide them with the needed tools, Cinderela has created and tested a methodology; surveying the waste-to-resource potential that considers every one of these perspectives. «The material flow analysis (MFA) performed in Spain, Slovenia, and the Netherlands, allows us to identify materials with economic potential for recycled aggregates like green concrete», says Ph.D. Sebastjan Meža, 6th work package leader. To conclude, this analysis, can be used for environmental impact assessments. It performs using an open-source and GIS supported tool GDSE (Geodesign Decision Support Environment). 

Lampoon, Cinderela, a Slovenian project
Cinderela is a Slovenian project whose goal is to make the urban construction sector more resource-efficient

Predicting optimal waste-to-product solutions

Customized to fit the MFA of different urban waste streams as sources of secondary raw materials. This tool enables predicting optimal waste-to-product solutions. These are based on waste availability, quantity, and location, and provides information on the administrations, owners, and managers involved. «A key characteristic of these materials is that they are not hazardous: their use poses no threat to the environment».

«After the lab tests, there is the need to implement new technologies, like our SRM-based construction products, in a real environment to see how they behave. For this reason, we will test and demonstrate them through pilots in Maribor, Skopje, and Madrid. Where we will build roads and facilities with SRM-based construction products». There, they will employ different types of waste, such as remains from the treatment of municipal wastes and industrial wastes. These will be turned in into SRM-based construction products. This is to say recycled and manufactured aggregates, recycled soil, and building composites.  

Building Information Modeling (BIM) to support construction phases

For the CiderCEBM, waste streams have been identified. The selection of potential urban waste occurs by applying end-of-waste technical criteria based on the materials’ intended use. Aggregates were subjected to various analyses. There was the performing of Standard chemical and mechanical tests on white and black slag. To make sure that it was possible to use said materials in road construction, and the white slag. In particular also as a partial replacement for cement in concrete mixtures for the production of blocks. 

For foundation slabs, base concrete, concrete in the walls of the ground floor, attic, and terrace walls, they will use alternative mixtures. Prepared and ready, waiting for the test in laboratories. To support all phases of construction, from the preliminary planning to the facility management and deconstruction, there will be therefore the utilization of the Building Information Modeling (BIM). There will be a case study analysis, quantity take-offs, and 6D facilities maintenance. These test results will not only help to design the modular and mobile pilot production plants for recycled and manufactured aggregates; building composite materials and recycled soils in the large-scale demos in Slovenia and Spain. They will also enrich the BIM library.

The environmental performance of the SRM based construction materials 

Using a life cycle approach including LCA and related methods, such as Social LCA and Life Cycle Costing; the CinderCEBM will ensure that this business model provides economic and environmental, and social added value. The evaluation of the environmental performance of the SRM based construction materials will occur using the Environmental Technology Verification (ETV) scheme. These assessments facilitate SRM- based construction products’ marketability; by confirming their innovation, performance, and the environmental benefits. They also allow a comparison between the new solutions proposed in CinderCEBM and the current ‘linear economy’ model; in terms of environmental-soundness and sustainability, economic viability, and social implications.

The Cinderela project will contribute to a 20 percent reduction of the environmental impact in the value and supply chain; by reducing the use of virgin materials and facilitating waste transformation into products. Adopting sustainable construction methods requires knowledge, time, and financial investments. Nonetheless, data from The World Green Building Trends 2018 Smart Market Report reveals that despite the barriers, green building is still growing globally. They expected nearly half of respondents to do the majority of their work green by 2021. With the pull of the market and the push of regulations acting as the main triggers for this change. CinderCEBM and CinderOSS can help construction companies and administrations to keep up with the time by taking part in the transition towards a green economy and society through eco-innovation. 


Cinderela is a Slovenian project whose goal is to make the urban construction sector more resource-efficient. Co-financed and implemented under the flagship of the Horizon 2020 European Financial Program; coordinated by the Slovenian National Building and Civil Engineering Institute (ZAG).

Slovenian National Building and Civil Engineering Institute

Dimičeva ulica 12, SI 1000, Ljubljana, Slovenia
[email protected]

Roberta Fabbrocino

The writer does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article.