LIGHTING QUALITY ASSESSMENT OF A HERITAGE LIBRARY: A CASE STUDY OF MONTGOMERY HALL, QUAID-E-AZAM LIBRARY, LAHORE

Heritage buildings adapted for contemporary library use often face difficulties in providing adequate and uniform lighting while preserving their architectural character. This study evaluates the lighting quality of Montgomery Hall, a historic Neo-Classical reading space within the Quaid-e-Azam Library, Lahore, with particular emphasis on illuminance, visual comfort, and compliance with recommended lighting requirements. A case-study methodology was adopted using field measurements, architectural documentation, a user questionnaire, and lighting assessment modelling. The study area was divided into a 3 m × 3 m measurement grid, and illuminance was measured at 20 points at a desk height of 0.75 m during daytime operating hours. Measured values were compared with recommended illuminance levels for reading, bookshelf, and circulation areas. A questionnaire survey was conducted to assess users’ perceptions of lighting quality, satisfaction, visual comfort, and reading conditions. Statistical analysis was performed using SPSS. The field assessment revealed spatial variation in illuminance. Areas adjacent to the large arched windows received higher daylight levels, whereas central and interior zones, particularly bookshelf areas, experienced lower illumination. Glare and excessive brightness were observed near window-adjacent seating. Questionnaire analysis indicated significant relationships between lighting-related variables and perceived visual comfort and satisfaction, with regression models statistically significant at p < 0.001. The findings indicate a performance gap between the existing lighting environment and contemporary library requirements. Conservation-sensitive interventions, including improved luminaire distribution, glare control, optimised daylight integration, and energy-efficient lighting controls, are recommended to enhance visual comfort and lighting uniformity while preserving the heritage character of Montgomery Hall.