This thesis presents experiments to integrate design practices for organisational change in a non-profit organisation in Brazil that contributes to the sustainable development of the Amazon rainforest region. The organisation that hosted this project is the Foundation for Amazon Sustainability (FAS). It is a civil society organisation that develops and implements environmental, social and economic projects within 16 Protected Areas for Sustainable Use and Manaus in the northern region. FAS aims to improve people’s quality of life by enhancing the socio-economic benefits of the forest and its biodiversity by disseminating sustainable practices and empowering local communities. Their work comprehends a wide range of activities, from giving technical support and mobilising resources to engage and influence public policy to support long-term sustainable development. This thesis initiated exploring how design can propose a human-centred process when the organisation is involved in policy-making matters. A literature research on design for policy and design value for organisation supported the project approach. The project followed a non-linear process and three guiding principles: collaboration, visual communication and experimentation. The work was carried out in two main streams: (A) supporting the FAS Public Policy team to redesign their involvement with policy-making matters; (B) disseminating designerly thinking and methods among the FAS workforce. The first stream started with several experiments that supported the redefinition of the problem. Then the focus turned to developing and testing methods to co-create an advocacy vision for the organisation. The second stream comprehends the development of workshops to introduce basic design ideas and give a hands-on experience on the design process. Both streams inspired interest in how design, especially its human-centredness nature, enhances FAS internal processes and supports delivering better services to the communities. This thesis presents the design practices that enhance the organisation’s work and the challenges of conducting a project remotely. Finally, the project gives recommendations to enable the adoption of design practices among the organisation workforce, such as making the departments boundaries more permeable, having management level support, and setting the environment and resources. In conclusion, the project contributed to the Public Policy team to view their work from a more integrated perspective with other departments. In addition, design practices such as creating artefacts and interactive meetings contributed to a positive work experience and collaboration. Following a non-linear process revealed to be more adaptable than traditional FAS project planning and the design human-centred nature was the most relatable to the organisation. Design practice involves, more than methods, tools and processes, finding ways to engage and propose action-oriented meetings that provoke critical questions. Finally, designers do not hold the solution to complex problems, such as sustainable development in the Amazon, but rather act as enablers in bringing diverse experts and people with lived experiences to build a more inclusive future.