A building lifecycle consists of multiple domains, and building information modeling (BIM) applications involve cross-domain knowledge exchange. In the knowledge spiral theory proposed by Nonaka, externalization facilitates knowledge exchange in designing cooperation, and a model library (ML) contains the necessary information for the architecture, engineering, and construction (AEC) industry. However, current MLs are centralized systems that are vulnerable to data tampering and copyright disputes, and the provided models may not match the requirements of current building projects. Therefore, this article develops a blockchain-based parametric ML (BBPML) for BIM collaboration to realize knowledge sharing. The parametric model in our ML can be flexibly applied to a project by adjusting the parameters. A blockchain network provides reliable storage and ensures the upload sequence. The research creates a website based on the proposed system through Ethereum and applies it to a curtain wall project.