<![CDATA[An optimal learning environment depends greatly on adequate lighting to support visual comfort, concentration, and students’ cognitive performance, particularly among young children. This study aims to optimize the classroom lighting of the GKI Sunter Sunday School in North Jakarta, a non-formal educational institution in an urban environment, through a quantitative intervention study. The initial measured lighting level was 87.5 lux, while the standard according to SNI 6197:2020 is 350 lux, indicating inadequate illumination and a level below the recommended minimum standard. The results of the pre-test perception survey involving 25 respondents (teachers, administrators, and students) also indicated discomfort, a dark classroom environment, and decreased learning interest, as reported by 88% of respondents. The intervention involved replacing the existing long downlight housing (18 cm) with a shorter downlight housing (12 cm), as well as increasing the LED bulb power to 12 watts (1,320 lm). This intervention successfully increased the average illumination level to 293.1 lux, representing a significant increase of 335%. Although the result did not yet meet the latest SNI 6197:2020 standard of 350 lux, the improvement reached the targeted optimization range of 250–350 lux and created a higher-quality learning environment. The post-test results showed that 96% of respondents felt significantly more comfortable with the new lighting, which was positively correlated with increased concentration and learning enthusiasm. This study contributes to the understanding of lighting quality in non-formal educational classrooms within an urban context and provides a measurable practical solution for GKI Sunter. ABSTRAK Lingkungan belajar yang optimal sangat bergantung pada pencahayaan yang memadai untuk kenyamanan visual, konsentrasi, dan performa kognitif siswa, terutama pada anak usia dini. Penelitian ini bertujuan mengoptimalkan pencahayaan ruang kelas sekolah minggu GKI Sunter, Jakarta Utara, sebuah institusi pendidikan non-formal di lingkungan perkotaan, melalui studi intervensi kuantitatif. Kondisi pencahayaan awal yang terukur sebesar 87.5 lux sementara standar menurut SNI 6197:2020 adalah 350 lux, menunjukkan iluminasi yang kurang memadai dan berada di bawah standar minimum yang direkomendasikan. Hasil pre-test persepsi 25 responden (guru, pengurus, anak didik) juga mengindikasikan ketidaknyamanan, kegelapan ruang, dan penurunan minat belajar (88% responden). Intervensi berupa penggantian rumah lampu dari tipe downlight panjang (18 cm) menjadi tipe pendek downlight pendek (12cm) serta peningkatan watt bohlam LED (12 watt, 1320 Lm) berhasil meningkatkan pencahayaan rata-rata menjadi 293.1 lux, sebuah kenaikan signifikan sebesar 335%. Meskipun belum mencapai standar terbaru SNI 6197:2020 (350 lux), peningkatan ini telah mencapai target rentang optimalisasi 250-350 lux dan menciptakan lingkungan belajar yang lebih berkualitas. Hasil post-test menunjukkan 96% responden merasa sangat nyaman dengan pencahayaan baru, yang berkorelasi positif dengan peningkatan konsentrasi dan antusiasme belajar. Penelitian ini berkontribusi pada pemahaman kualitas pencahayaan di ruang kelas pendidikan non-formal dalam konteks perkotaan dan memberikan solusi praktis yang terukur bagi GKI Sunter.]]>
