Vertical densification and indoor comfort: a perceived indoor environmental quality assessment of ground-floor living spaces in Swarna place, Colombo

Abstract

This study investigates the Perceived Indoor Environmental Quality (PIEQ) in ground-floor living spaces within Swarna Place, a low-income incremental vertical housing settlement in Colombo, Sri Lanka. It evaluates four core environmental parameters: thermal quality, acoustic quality, air quality, and visual quality with lighting: using a validated questionnaire structure adapted from widely applied assessment scales to suit the socio-spatial context of multifunctional ground-floor living rooms. The research focuses on four development stages (Stages 01, 03, 05, and 07) observed during long-term settlement evolution. Findings from 60 surveyed households indicate a steady decline in perceived indoor comfort across stages, particularly in thermal and air quality aspects. This decline is closely linked to spatial densification, enclosed facades, and reduced natural light and ventilation due to vertical expansion. The study highlights the critical need to maintain environmental quality during housing transformation and suggests practical design measures for future low-income vertical housing developments. These findings contribute to broader discussions on residential experience, adaptive space use, and sustainable indoor environments in high-density urban communities.