Contributions: This study examined the effectiveness of making activities in fostering the competency development of school-age children engaged in a making program. The findings suggest that community-based makerspaces can provide autonomous and informal learning experiences, facilitating their competence development. When integrated with formal learning in schools, these experiences can facilitate a well-rounded education that nurtures 21st century skills in the younger generation. Background: The making program, hosted by community youth centers in Hong Kong, comprised a series of five workshops. These workshops provided guidance throughout the creative processes, encouraging participants to invent artefacts under the theme of "smart design for living." Research Questions: What generic skills and other attributes can school-age children develop through making activities? What factors influence their development of generic skills and other attributes? What disparities emerged between their community-based and school-based making experiences? Methodology: The study utilized a mixed-method approach, encompassing of a pre- and post-test questionnaire survey involving school-age children who took part in the making workshops (N = 232), as well as semi-structured interviews with a subset of the participants (n = 25). Findings: Survey results revealed significant enhancements in participants' information technology skills, communication skills and divergent thinking, along with a favorable acceptance of the making tools. Pertinent topics related to competency development, including age-related effects, computer accessibility, and mobile device ownership, were examined and discussed within the context of the study.