Comparative Study of Low-income Housing Construction in Pakistan Based on Life Cycle Assessment

Abstract

Pakistan faces a critical housing shortage exceeding 10 million units, with low-income households disproportionately affected, often residing in substandard informal settlements. Conventional construction methods, relying on fired clay bricks, Portland cement, and reinforced concrete, are energy-intensive and environmentally damaging, contributing to high carbon emissions and long-term economic burdens. This study employs a life cycle assessment (LCA) framework to evaluate four low-income housing construction scenarios: conventional fired clay brick systems (S1), fly-ash brick systems (S2), compressed stabilized earth block (CSEB) systems (S3), and bamboo hybrid systems (S4). Using a 50 m² prototype housing unit, the analysis integrates environmental, economic, and social dimensions through LCA, life cycle costing (LCC), and the fuzzy analytic hierarchy process (FAHP). Results indicate that CSEB systems (S3) achieve a 48% reduction in embodied carbon and a 45% reduction in lifecycle costs compared to conventional systems, while bamboo systems (S4) offer renewable benefits despite higher initial costs. Fly-ash bricks (S2) provide moderate improvements, but their reliance on coal byproducts poses sustainability risks. The study advocates for policy reforms, including LCA integration, passive design mandates, and subsidies for sustainable materials, to deliver affordable, eco-friendly housing solutions for Pakistan’s low-income communities.