Existing tendering methods for construction projects are centralized and rely on a third party's involvement during the process, hence, the methods raise critical concerns regarding data security, transparency, and traceability, as the bidders have to trust the organizer for the legitimacy and fairness of the process. This paper focuses on how the recent developments in decentralized blockchain technologies can be adopted for tendering of construction projects to improve the traditional process by eliminating intermediaries and ensuring transparency as well as data security. A novel, decentralized blockchain-based tendering system is presented for construction projects, leveraging (i) decentralized smart contracts to execute the tendering steps, including storage of the information throughout the process, management of the bid bonds, evaluation of the bids, and awarding of the contract according to the preset conditions, (ii) blockchain-integrated decentralized storage systems to exchange and store off-chain documents that are related to tendering, and (iii) decentralized application to facilitate the participants' interaction with the proposed system during the tendering process. The proposed system presents a new method for achieving a decentralized, secure, trustworthy, and transparent tendering environment among project participants. The outcomes of the system indicate the potential of future blockchain research for achieving autonomous and decentralized tendering sytems.