Annual theme


Subscribe to
our mailing list

* indicates required


City of Zagreb
City Office for Physical Planning, Construction, Communal Affairs and Traffic


Faculty of Architecture
University of Zagreb


City Acupuncture


Oris - House of Architecture




City of Zagreb
City Office for Culture, Education and Sport


Republic of Croatia
Ministry of Culture

Work title: Inverting the periphery

As enclaves of wealth have formatted the cityscapes of Middle East, influx of immigrants to informal arrival slums have paralleled these development. As the difference between global and the local has been flattened, spatially isolated communities have became empowered to developed global identities and local markets for exchange. As resistance to external market forces novel parallel modes of exchange have overwhelmed these logics. Subtraction Coin is a commodity backed crypto currency designed for the Boulaq al Dakrour material market of collection, transportation and transaction of glass, plastic, stone and metals. The informal neighborhood of Boulaq al Dakrour, on the outskirts of Cairo, is known for its rich history of trading materials and generating internal value. While the neighborhood was once spatially isolated from the rest of the city it is worth reflecting on the source of spotlight within worldwide markets. The changes the neighborhood has seen is due to an architectural initiative, known as Substraction Coin, that was layered over the historic informal material markets to enable a local currency for global exchange. This project is a retrospect of past urban situations in Cairo as well as a brief overview of how the currency works. While the first generation of cryptocurrencies were volatile in price, a class of material asset backed coins have emerged to ensure a stable price floor, giving trust to the market and a foundation for appreciation in value. Thus, Subtraction Coin can be traded on the open market. It is a cliché by now to say that the bitcoin protocol had upended conventional notions of value through thinking in blockchains. The blockchain as a mode of thought allowed any flow of information, change in space or market transaction to be recorded on a trustless public ledger. While bitcoin applied this logic to currency, numerous forks of the protocol have allowed for distributed autonomous corporations to conduct services such as issuing stocks, trading deeds and executing contracts as a decentralized phenomenon. All coins are a finite resource and coins are minted and enter circulation through the act of mining. Miners are responsible for publishing the public ledger and recording all transactions within the network. The publication serves as a proof of their mining work and miners are paid in blocks, which hold a random value of coins. Subtraction Coin was pre-mined. This means a certain number of coins were mined before mining was available to the public. These coins were set aside to be distributed to the residents of Boulaq al Dakrour who wished to participate. This form distribution is known as an “air drop”. When cryptocurrency miners around the world begin mining the remaining amount and trading the coin on exchanges the value appreciated. As the date of the airdrop neared speculation and excitement drove the price to unfathomable levels. By circumventing the centralized fiat currency of Egyptian pound, subject to volatility by International Monetary decree, value was distributed to the residents of Boulaq al Dakrour for free. Subtraction Coin is used locally, but owned and traded globally. More than a means of tracing material exchange, Subtraction Coin allows holders to also send anonymous votes through the system to affect the flow of material towards desired urban projects. This has allowed direct participation in urban change. Not long after the “air drop” miners from around the world uncovered all coins, releasing the full supply into traceable circulation. However, mining for blocks was then translated to the local and material level. When residents chose to remove parts of their business or home for voted on projects the material was traded for Subtraction Coins. The process of subtraction starts with acupuncture like interventions around the neighborhood, opening space on pressure points. The process is spread around through informal collaboration through word of mouth and rumors. As a open source project anyone holding Subtraction Coin can propose and vote on projects. This has opened the neighborhood and established connections to other cultural cores of Cairo, drawing residents back to the city from desert compounds. The value of Subtraction Coin is their ability to fund and power profoundly impactful projects. What permitted such a smooth transition to the coin during the airdrop was the architect’s willingness to demonstrate and explain on site. The power of Subtraction Coin comes from the network and the intelligence, integrity, and passion of all the people working to build a more enjoyable place of people, and profits.
back to list