Sustainability has been disturbed heavily in recent years through various human actions, and solutions are urgent; the need to cooperate with common sustainable goals among municipalities, countries, and continents is crucial. The path of global sustainability starts with local sustainability, and how it could be achieved by municipalities is the main goal of this thesis. There are many challenges a city may face in all three (3) pillars (environmental, social, governance), and it is probably impossible to find a solution that eliminates all of the challenges simultaneously. Still, every project that acts towards sustainability is helpful, and it can have an impact regardless of the cost or the area, as shown by real examples of projects that strive towards sustainability. New ideas that challenge the norm while understanding the nature and people are the leading path for innovative changes, hopefully gradually replacing outdated and stagnant systems. An unsustainable, unsolved, and suffering part of municipalities is homelessness. Incomplete, stagnant help is not enough; homeless people are not just a percentage on paper. They need complex support from the state to reintegrate successfully into society. An innovative project proposal to eliminate homelessness in the municipality of Athens focuses on establishing a government building with a different management and organisation approach. Defining the “Vision and Goals” and Leading a holistic approach, it considers the economic, social, mental, physical, and practical difficulties homeless people face every day and offers sustainable solutions to overcome them permanently.