# BBBlockchain Token Incentivization for Citizen Participation

> Berlin housing associations degewo and Gewobag, together with TU Berlin, tested a blockchain-based system to increase citizen participation in urban construction projects. Participants received tokens as rewards for their feedback and votes through an app and could redeem them for free coffee. However, only 6% of the 81 participants actually redeemed their tokens, showing that tokens did not serve as a primary incentive mechanism.

**Sector:** Tertiary sector · **Industry:** Coworking and shared services · **Organisation:** degewo, Gewobag, TU Berlin · **Maturity level:** Pilot

Canonical URL: https://www.sapientblock.com/en/use-cases/degewo-mieter-token-beteiligen

## Documentation status

- **Project status:** Pilot
- **Evidence:** Evidence high
- **Editorial review:** Ufuk Avci, 15 April 2026

## Description

BBBlockchain is a blockchain-based online participation platform developed by the Einstein Center Digital Future (ECDF) in Berlin with involvement from TU Berlin (Prof. Florian Tschorsch, Prof. Jochen Rabe). The platform uses the Ethereum blockchain and operates its own public blockchain fork on three servers (TU Berlin + degewo + Gewobag). Smart contracts (if-then rules) enable direct resident participation without intermediary authorities. All participation data is stored immutably.

BBBlockchain is an interdisciplinary research project of the Einstein Center Digital Future (ECDF) — a consortium of six Berlin universities. The project is supported by all six municipal housing associations in Berlin. It was tested in two real construction projects: (1) degewo Kietzer Feld — platform live since late 2019, (2) Gewobag Bülow90 — online since February 2020. Technically, the platform is based on the Ethereum blockchain with its own public blockchain fork; three servers (TU Berlin, degewo, Gewobag) operate the network. The app is available in the Apple App Store, Google Play Store and via web browser. Smart contract code is open source on GitHub. In phase 1, construction progress information and news were initially published to create transparency. In phase 2 (2022), further participation formats were tested. ECDF Professor Florian Tschorsch: "Through the BBBlockchain app, we were able to reach a new target group — this is not necessarily related to the blockchain technology itself, but to the additional digital communication channel."

## Benefits

- Cost reduction in citizen participation processes through digital automation and reduced rework in planning phases.
- Convenient digital participation options in urban development processes via mobile app use.
- Transparent and comprehensible documentation of all citizen participation processes through blockchain technology.
- Digital participation opportunities enable more flexible citizen involvement in terms of time and location.
- Reduced administrative effort through automated recording and evaluation of citizen feedback.
- More efficient workflows through digital tools and automated documentation of participation processes.

## Challenges

- High initial investments for blockchain infrastructure and development of specialised apps for citizen participation.
- Low acceptance of token incentives, as only 6% of participants redeemed their rewards.
- Complex technical implementation requires specialised blockchain knowledge and corresponding development resources.
- Need for extensive training for staff in handling new blockchain-based participation tools.

## Technology foundation

The system initially used the Ethereum testnet Rinkeby and later migrated to a private blockchain network on servers of degewo, Gewobag and TU Berlin. Smart contracts were used for timestamping, voting logic and token management to enable transparent and comprehensible citizen participation processes.

## Sources

- [BBBlockchain Final Report](https://bbblockchain.de/publications/BBBlockchain-Final-Report.pdf)
- [Transparente Stadtentwicklung: BBBlockchain legt Abschlussbericht vor (Archivversion)](https://web.archive.org/web/20260213112154/https://www.digital-future.berlin/en/news/news-in-detail/news/transparente-stadtentwicklung-bbblockchain-legt-abschlussbericht-vor/?tx_news_pi1%5Bcontroller%5D=News&tx_news_pi1%5Baction%5D=detail&cHash=5a03efe2774fb2178012e0ae867dfb1f)
- [BBBlockchain Projektseite](https://www.digital-future.berlin/forschung/projekte/bbblockchain)
- [BBBlockchain Handlungsempfehlungen](https://bbblockchain.de/wp-content/uploads/2020/06/BBBlockchain-Handlungsempfehlungen.pdf)