Collaborative and participatory design (C&PD) is an area of design theory and practice in which designers involve project stakeholders as active participants to jointly explore and frame problems and to co-create solutions. In response to increasingly more pressing sustainability challenges, C&PD scholarship has been engaged in rethinking the premises, constructs, and practices of the field. One of the ways in which C&PD is striving to address the sustainability challenges is by including natural nonhuman stakeholders. Such an approach warrants a careful and evaluative investigation.

Therefore, this doctoral dissertation critically explores in what ways including natural nonhuman stakeholders in C&PD can contribute to sustainability. It seeks to answer four research questions. (1) Why should designers include natural nonhuman stakeholders in C&PD when aiming to contribute to sustainability? (2) How to approach the identification of natural nonhuman stakeholders in C&PD when aiming to contribute to sustainability? (3) In what ways can natural nonhuman stakeholders be included in C&PD? (4) How to approach the identification of natural nonhuman needs? This dissertation includes two parts: five peer-reviewed research publications form one part, and a six-chapter introductory essay forms the other part. The essay answers the research questions by integrating and discussing the findings, summarizes the results, and outlines limitations and avenues for further research.

The doctoral research findings indicate that including natural nonhuman stakeholders in C&PD when aiming to contribute to sustainability has merit; however, it requires being critical and careful when identifying the stakeholders, including them in C&PD processes and sourcing their needs. Including natural nonhuman stakeholders can contribute to sustainability in three interrelated ways: by shifting individual and collective worldviews towards being more aligned with sustainability; by challenging the dominant systems and structures that support unsustainability; and by creating practical design solutions that are more aligned with and support sustainability. The dissertation discusses these three reasons and proposes an integrative framework showcasing the interdependencies and interconnections between them. Further, the dissertation proposes a systemic approach and the usefulness of non-anthropocentric environmental ethics to identify natural nonhuman stakeholders. Then the dissertation presents three ways designers can use to include natural nonhuman stakeholders in design time and discusses natural nonhuman stakeholder participation in the use time. Finally, because natural entities are rarely discussed in relation to their needs and research disciplines do not necessarily identify needs of natural nonhuman stakeholders, the dissertation suggests that designers should attentively approach the identification of needs of the natural nonhuman stakeholders in their projects.