Participatory Architecture (PA) stands for the democratisation of architectural design processes. Architects employ designerly engagements to build power-balanced relationships with communities, where everyone can design. This paper explores previous and ongoing PA projects with focus on uncovering hidden challenges and optimal conditions to inform current approaches. PA emerges in the 1960s as a reaction to the Modern Architecture, which has disconnected contemporary architecture from laypeople’s needs and situations. Evidence can be found in the spatial appropriations after Le Corbusier's intervention in Pessac (Bordeaux), the Smithson’s Robin Hood Gardens (London), and the Yamasaki’s Pruitt-Igoe (St. Louis). This has led to architectural designs that, in many cases, exclude consultation with their end-users. Since that, activists, sociologists, architects, urban planners, and anthropologists have been encouraging citizenship participation in architecture. Previous experiences, such as Fathy's New Gourna Village (Luxor) and the “Tondo” competition (Manila), reflect that promoters’, architects’ and the communities’ aspirations need to be crafted based on dialogues. Otherwise those physical transformations would not fulfil their inhabitants’ needs. In this regard, the architect might adopt a mediating role. Good current practices can be found in Latin America, such as Aravena’s Elemental (Chile), and Ecosistema Urbano’s Asulab (Asunción). In Europe it resonates Cirugeda’s Recetas Urbanas (Sevilla), Concordet’s Ensemble à Claveau (Bordeaux), Hands-on-Bristol, and Assemble’s Granby Four Streets (Liverpool). The paper reviews these strategies that push the boundaries of participation in architecture. This aligns with an emergent society eager to participate which underscores the need for holistic research to envision PA future practices.