The New Zealand commercial construction industry predominantly employs the traditional Design-Bid-Build (DBB) contract process, where design and construction responsibilities are separated. This often results in design errors and omissions, leading to significant cost and schedule overruns. However, the Design-Build (DB) contract process, which integrates design and construction under a single contractor, is gaining traction. In this model, the contractor assumes financial and schedule risks once the client approves the budget. This study employed a multi-case research approach to compare the DBB and DB contract processes. Data were collected from eight projects completed by an Auckland construction company and evaluated against key performance indicators. Additionally, interviews with key stakeholders provided insights into the performance benefits and challenges of each contract process. The findings reveal that stakeholders adhere to familiar contract processes, negatively impacting the industry. The DB process was found to mitigate cost and schedule overruns more effectively than the DBB process. It facilitates early collaboration between the contractor and project team, addressing design errors and buildability issues upfront and ensuring smoother project execution. The DB process is particularly effective for small- to medium-scale, less complex projects, while the DBB process remains suitable for large, complex projects requiring substantial client input during design.