The construction sector is changing, and commissioning organisations have to rethink the way they approach the market. This is especially important for client organisations operating in the public domain, because of their role as change agent in the sector and their social responsibilities. The ‘Public Commissioning Maturity Model’ (PCMM), first presented in 2014, was created to raise awareness amount construction clients’ organisations to the range and width of their commissioning task. It provides a means to elicit discussion on the current and desired state of the organisation’s competences, thereby supporting these organisations in further professionalization. As a result of six workshop-based discussion sessions and five panel discussions, the value of the model was determined. In this paper, the validation path of the model in practice is described. The findings resulted in changes to improve the usability of the model for the construction sector, as well as alterations to increase the understanding of the model for workshop participants. Adjustments regarding stylistic issues and elements in the maturity model and supporting materials were also made. Applying the PCMM has proven to enable assessment of the current and desired organisational performance on different aspects of public commissioning by eliciting discussion and raising awareness. It is however not constituted for numerical ranking, sector-wide monitoring or benchmarking purposes, while these needs also exist among client organisations. Furthermore, it was found that the model is less suitable for organisations in the middle of a comprehensive change process.