Land is a limited resource: In London, it has led to a severe housing crisis. Since Britainβs housing market experienced a rush of privatization in 1980, the building stock of affordable housing has grown less than the demand. I developed an online game prototype for a crowdsourcing game aimed towards building a reliable database of land capacities in London. The game prototype was evaluated based on two aspects: Firstly, whether a game can create an entertaining experience for players and secondly, whether it can generate reliable data. Check out the Github Repo.