Life Cycle Assessment of Hybrid Vernacular-Modern Technologies: A Comparative Study of the Ecofordable House and Conventional RC Structures

Nermine Abdel Gelil Mohamed ^1,2*

• ¹ Effat University, Jeddah, Saudi Arabia
• ² October University for Modern Sciences and Arts, 6th of October City, Giza, Egypt

This paper investigates the environmental benefits of adopting hybrid vernacular-modern building technologies, through a detailed Life Cycle Assessment (LCA) of a residential prototype known as "Ecofordable House" (EH). EH integrates hybrid techniques, including partially-reinforced interlocking compressed stabilized earth brick-walls (ICSEB), jack arch and funicular shell-roofing systems, and date palm midrib components. Its environmental impacts are compared to a reinforced concrete house (CH) as the baseline conventionally adopted in the Middle East. The LCA follows a cradle to grave scenario, covering A1-A4, B1-B5, and C1-C4 stages, with additional reference to stage D. The results showed that EH has a Global Warming Potential of 368.17 kg CO₂e/m², while CH has a value of 698.22 kg CO₂e/m², which represents a reduction of about 47% in GWP. Fossil-based emissions in the EH are 46% lower, biogenic emissions are reduced by 91%, and LULUC has a reduction in its impacts by 82%. The Acidification Potential is 43% lower while eutrophication across freshwater, marine, and terrestrial is 28% to 44% lower. The POCP is reduced by 43%, and the Resource depletion impact for elements and for Fossil Fuels is reduced by 50% and by 43%. Water use is 18% lower. Material production (A1-A3) is identified as the primary driver of environmental impacts for both prototypes. Fired clay bricks, concrete, and reinforcement steel are the major contributors towards GWP for CH, while Portland cement, concrete, and reinforcement steel dominated the GWP for EH, but with much lower values due to their reduced quantities. For CH, the major building parts' contributors are the foundation, roofs, and external walls; while in the EH, foundations (conventional RC) and external walls are the major contributors. These results have supported the significant environmental benefits of adopting hybrid modern and vernacular building technologies and materials as ways of reducing the environmental impacts while ensuring more durable and structurally sound buildings in hot arid climates.