This research investigates how capacity-building interventions might be designed and implemented to enhance strategic sustainability work in municipal contexts and address institutional capacity deficits hindering effective sustainability transitions. Drawing from a blend of secondary and primary data sources, including semi-structured interviews and surveys, our study employs a conceptual framework to identify considerations crucial for effective, responsive, and transformative capacity-building efforts. Results reveal the significance of fostering a robust capacity-building culture, understanding context-specific engagement styles (learner archetypes), and utilizing a combination of approaches tailored to context-specific needs. This study also suggests the interdependence of goals and values across the four levels of strategic sustainability action and transformation (individual, organizational, network and systems level), emphasizing the importance of accounting for all four levels in the cultivation of a supportive capacity building culture and promoting a strategic approach to capacity building planning and implementation, balancing short-term objectives with the pursuit of long-term transformative outcomes. Findings contribute valuable insights for capacity-building planners and interveners involved in the design and implementation of continuous capacity building efforts aimed at enhancing strategic work of diverse actors engaged in sustainability efforts.