Georgetown, the capital of Penang Island, records the second highest density in Malaysia. On the other hand, those with lower economic status mostly live in low-cost, high-density vertical housing with indoor and outdoor environmental quality. Such housing conditions have severe implications on the residents’ comfort. Hence, this study adopted the mixed-method approach to assess indoor and outdoor air and lighting quality in high-rise low-cost housing. The qualitative approach was deployed to observe three low-cost high-rise housing in Penang while the second approach was quantitative data collected using a survey questionnaire distributed to households in the case study area. This study aims to identify the current environment indoor and outdoor lighting quality in low-cost high-rise housing. The three low-cost housing areas investigated in this study, namely, Taman Ampang Jaya (TAJ)(Seberang Jaya Utara (SPU) district), Halaman Kenanga (HK)(Daerah Timur Laut (DLT) district), and Idaman Seroja (IS)(Daerah Barat Daya (DBD) district), had more than 200 units. Resultantly, the three-housing had an average air and lighting quality, whereas the corridor indicated poor lighting, as well as foul and unhealthy air. Indoor and outdoor air quality and lighting in high-rise housing are related to the environment surrounding the site.