Three groundbreaking ideas to rethink waste in construction

In 2018, Danish philanthropic association Realdania launched the “Circular Construction Challenge” to kickstart the circular transition in the built environment.

The construction sector generates almost half of the world’s waste. The three winning solutions demonstrate new ways of upcycling, recycling and reusing waste, turning it into a new resource.

Rethink Waste

We want to help build a zero-waste world. A world where we minimize waste and reuse, recycle and upcycle existing waste – everything from plastic bottles to used bricks from a roof renovation.


Collaboration is key to creating game-changing and lasting solutions. The solutions in Circular Construction Challenge come from global partnerships across the value chain. Each team has strengthened each other’s ideas, competencies and resources.


Circular Construction Challenge turns the best ideas into solutions that make waste a valuable resource. That includes products, materials or components, and new approaches that seek to rethink, redesign and reuse waste.

Vision and impact

What is the Circular Construction Challenge?

The Circular Construction Challenge addresses the global problem of waste overload, mass consumption and continuously increasing resource use. In August 2018, we called for innovators to help solve the problem by reducing waste in the built environment. The challenge program was a one-year process altogether and included a six-month innovation process for the three winning teams to turn their ideas into new solutions for the market.

Who participated?
Material pioneers, designers, engineers, architects, craftsmen and construction companies - startups, SMEs and corporates - business innovators and tech experts joined the Circular Construction Challenge. We received a total of 39 submissions from Danish-based companies with commercial ambitions for their idea. Subsequently, a wide range of stakeholders from all over the world joined and helped the finalist teams create their solution prototypes.

What is a good circular solution?
We were open to all ideas — no matter what stage of development they were in. As long as they — with support, new partnerships, prototyping and tests — were able to advance and scale the solution radically. A good solution should also take both sides of the value chain into consideration: what type of waste is removed from the equation and what resource is then added?

What has happened so far?
Out of the 39 submissions, 6 finalist ideas were selected and announced at Building Green conference in October 2018. The 6 finalists developed the ideas and the teams of collaborating partners from the value chain. Through a workshop about circular business models, the teams worked on circular innovation potentials for their ideas and from their proposals, 3 winning teams were chosen by the international selection committee. Furthermore, 36 ideas in the Circular Construction Challenge were ‘runner-ups’ - all with a great potential for being developed through other platforms. See all original applicants on the submission site here.

The Challenge Call

You can read all the details about the competition by downloading the challenge call.

Challenge timeline

The Circular Construction Challenge runs in four phases throughout 2018-2019. The first phase was the submission phase, where companies were invited to respond to the challenge call and send in their idea. In the second phase, we selected the 6 finalists who received support to match and set the right innovation teams. 3 winning teams were chosen for a six-month long innovation phase to produce and showcase their prototypes.

Here are the most important dates and deadlines:

Phase 1

Challenge call and response

August 24, 2018 — Launch of challenge call & application period for innovators

At the kick-off event in BLOX, Copenhagen, we launched the challenge call and explained the process.

October 8, 2018 — Submission deadline for ideas and solutions

We were happy to receive 39 ideas.

Se all submitted ideas
Phase 2

Selection & match

October 23, 2018 — Pitch day for the shortlisted solutions

Up to 10 shortlisted candidates pitched their idea to the selection committee.

October 31, 2018 — Announcement of the finalists

Up to 6 finalists were announced at the Building Green Conference in Copenhagen, where each candidate did a lightning talk about their idea. The audience were to invited to ask questions or express their interest in joining one of the teams.

See all six finalist ideas
November 1, 2018 — Application period to join as a team member opens

Danish as well as international businesses, startups, organizations, waste suppliers, researchers etc. were invited to join one of the 6 teams.

December 3, 2018 — Application deadline to join as a team member

We were happy to receive 81 applications from around the globe.

January 15, 2019 — Application deadline for the 6 teams

The 6 finalists submitted their team profiles, MoUs and business plans.

Late January — Selection of the 3 winning teams

The 3 winning innovation teams were announced on February 5, 2019.

Phase 3
For the winners

Innovation & co-creation
6 months innovation process

Feb 2019 — Bootcamp #1
May 2019 — Bootcamp #2
Jun 2019 — Bootcamp #3
Phase 4
For the winners

Dissemination & global scale

Fall 2019 — Participation in relevant international events

Together, we will find the relevant international events for the 3 winning teams to participate in, to gain access to international network and potential buyers.

December 2019 — Showcasing and dissemination of prototypes

The 3 innovation teams will get the opportunity to showcase their prototypes and get access to national and international key stakeholders such as investors, buyers and organisations.

The prize

The winning teams will receive substantial, long-term development support comprised of the following:

Six months of charged innovation

The winners received exclusive access to a six-month-long charged innovation process that included three boot camps, where the newly established teams used co-creation and expert guidance to take the solution to the next level. Throughout the programme, the winners received tailored mentoring from domain experts to support the prototyping phase, including access to labs and prototyping facilities.

Up to DKK 1,000,000 for development costs

The winners received up to DKK 1,000,000 (€130,000) to support the development of a physical prototype. The financial support covered expenses for materials, purchase of data, travel costs and working hours.

Extended network and partnerships

The Circular Construction Challenge was also an opportunity for the participating businesses and organizations to connect with national and international networks, to get access to new partnerships throughout the value chain and to get solid PR and branding. Winners had access to dialogue and feedback sessions with a panel of potential buyers and investors for the new solutions.

Why the Circular
Construction Challenge?

A growing world population and massive global urbanization has made the building industry among the fastest-growing in the world - and one of the biggest waste generators. Globally, 1.3 billion tons of solid waste is produced every year. Building materials account for half of the solid waste generated worldwide, according to The World Bank. In a world with unprecedented pressure on our planetary resources, this calls for immediate action. The Circular Construction Challenge taps into several of the UN Sustainable Development Goals by supporting new solutions for a world without waste. A zero-waste world in which all waste goes into a circular system as a resource, helping build capital rather than reduce it.

1.3 billion tons

solid waste produced globally every year

€6 billion

is what Denmark could gain annually by going circular


of the world's CO2 emissions come from the building industry


of the Danish resource use is spent by the construction sector

2.2 billion tons

is the expected production of solid waste annually by 2025

4.3 billion

is the number of urban residents in the world by 2025

518 kg

is how much trash every person will generate yearly in 2015, according to The World Bank

1.8 tons

was the average waste generation per EU-citizen in 2014

11.3 million tons

waste was produced in Denmark in 2015

of all waste generated in Europe
derives from the building industry

1.3 billion tons

solid waste produced globally every year

€6 billion

is what Denmark could gain annually by going circular


of the world's CO2 emissions come from the building industry


of the Danish resource use is spent by the construction sector

2.2 billion tons

is the expected production of solid waste annually by 2025

4.3 billion

is the number of urban residents in the world by 2025

518 kg

is how much trash every person will generate yearly in 2015, according to The World Bank

1.8 tons

was the average waste generation per EU-citizen in 2014

11.3 million tons

waste was produced in Denmark in 2015

of all waste generated in Europe
derives from the building industry

Selection criteria

The submitted ideas and solutions were assessed by our expert selection committee and judged according to the following criteria.


What makes the solution circular?
— Which type of waste does the solution reduce?
— How large is the waste fraction that you reduce?
— How much can you reduce this fraction? How big is the upcycled part?
— Why is this type of waste fraction particularly important to reduce?
— How big is the potential improvement offered by your solution?
— How big is the CO2-reduction of your solution compared to a conventional approach?


What is the visionary aim of the solution?
— What makes the solution new or even radical?
— How does the solution differentiate from other solutions on the market?

Value creation

What value do you create for the user, the planet and society as a whole?
— Who are the primary customers and users?
— What is the target market for the solution, for example geographically?
— What is the business model for the solution, and what makes it circular?
— What social, economic and environmental gains does the solution achieve?
— Which of the UN Sustainable Development Goals does the solution address?


What is the market potential of the solution?
— How big a market does the new solution appeal to?
— What does it take for the solution to reach the market and scale?
— How can new technologies help speed up the production or scale the solution?


Who is contributing to the solution?
— How does the solution involve the different parts of the value chain? And how does the solution include the value chain in order to optimize its own potential?
— What partnerships are built around the solution, if any yet?

Selection committee

Our distinguished Selection Committee is comprised of leading Danish and international experts within circular economy, innovation, waste minimization and construction.

Ann Rosenberg

Senior Vice President & Global Head of SAP Next-Gen

Ann Rosenberg leads SAP Next-Gen, a purpose-driven innovation university and community aligned with SAP’s commitment to the 17 UN Global Goals for sustainable development. Ann is the global lead for #sheinnovates in collaboration with UN Women. She was voted top 20 blockchain female influencers in 2017.

Ken Webster

Senior Lecturer at the Centre for Circular Economy, University of Exeter, UK

Ken is a Visiting Fellow at Cranfield University and Guest researcher Linköping University. Ellen MacArthur Foundation Associate.

Frido Kraanen

Principal Director Societal Impact, PGGM

PGGM is a Dutch pension service provider, working for multiple pension funds, with €220 bln AUM and working for 3 million participants. Frido is responsible for the PGGM’s cooperative principles, their societal agenda and corporate sustainability program.

Christina Lindbäck

Senior Vice President of Corporate Sustainability for the NCC Group

Christina is managing the strategic work with sustainability issues with in the NCC Group. She is also the Chairperson of the Board of the Swedish Company Miljömärkning Sverige AB and a member of the Board of Axfoundation.

Christian Bason

CEO, Danish Design Centre

Christian sets the strategic direction for the Design Centre and governs the demanding initiatives and activities. Christian is also CEO of Design Society and a member of the board for the Royal Danish Academy of Fine Arts, School of Architecture, Design and Conservation (KADK) and The Rockwool Foundation’s Research Programme Committee.

Toke Falk Sabroe

Partner in Leaderlab

Toke has for nearly 20 years been involved in international cross-sector innovation projects - within both technical and creative areas. Toke Sabroe is among others co-initiator of the global LAUNCH Circular platform, and the Sustainable Build partnership.

Steen Michael Asgreen

Senior Relationship and Network Manager, The Danish Growth Fund

Steen is also Partner at the board network BoardPartner and Co-founder in the startup company He is a member at advisory boards at Connect Denmark and the RealDania program – Innovation to market.

Lisbeth Chawes

CEO, Esoft

Lisbeth is a Danish tech leader and entrepreneur with over 15 years of experience from management positions and startup companies within the tech industry. She is among the top fifty high-profile women in the Nordics. Award-winning leader, Board Member, Speaker & Mentor.

Antonis Mavropoulos

Founder and CEO of D-Waste and President of ISWA

Antonis has been involved in solid waste management projects for 20 years. His recent research deals with the fourth industrial revolution and the transformation of the waste & resources sector. He has invented the Waste Atlas, a global interactive waste management map in cooperation with GIZ SWEEPNET, ISWA, WTERT, SWAPI and Leeds University.