The I-DECOBEST Module represents an innovative approach to sustainability education, integrating energy literacy, environmental stewardship, and interactive learning activities for primary school students. This study focuses on the content validation of the module, employing the Content Validation Index (CVI) for each activity to ensure alignment with pedagogical standards. Quantitative findings reveal high CVI scores across all activities, with values ranging from 0.85 to 0.95, indicating excellent validity. Qualitative feedback from experts highlights the module's strengths in combining theoretical and practical components, particularly its hands-on tasks such as circuit building and group-based problem-solving. The inclusion of sustainability-focused activities, such as renewable energy simulations and energy conservation discussions, further enhances its relevance and impact. Students reported increased engagement and understanding of core concepts, whilst teachers noted improvements in energy literacy and critical thinking skills among participants. The study emphasizes the importance of quantitative validation and qualitative insights in refining educational modules. Findings demonstrate the effectiveness of the I-DECOBEST Module in fostering attitudinal shifts and knowledge retention, aligning with global educational goals for sustainability. Recommendations include iterative refinements to incorporate emerging technologies and expanded activities to deepen learning outcomes. This research contributes to instructional design by providing a validated framework for integrating sustainability into primary education, offering actionable insights for educators and policymakers.