  In Spain, quantity surveyors are entitled to carry out official cadastral
surveys, attestations, and certificate issuing according to a well-defined
professional code. Official Associations of Quantity Surveyors and Technical
Architects (COAAT) are responsible for endorsing the documentation related to
actions performed on buildings. An e-platform that enables immutability,
traceability, and a unique property record among all the Spanish COAATs, with
an affordable cost, is essential to streamline the involved processes.
  The blockchain technology and smart contracts have recently emerged as
promising solutions for e-government services due to the inherent features
provided by the technology. In this paper, we identify the design goals and
propose a blockchain-based e-government system for the electronic management of
the documentation generated, submitted, and validated by the Spanish COAATs,
namely, the COAATChain. The proposal has been deployed and evaluated on the
Binance testnet blockchain, in order to assess its affordability.
