Investigation of energy performance of a rammed earth built residential house in sub-tropical, tropical and temperate climates of Australia

Abstract

Purpose / Context - This paper will examine the predicted energy consumption (MJ/m2) of a resi-dential house made of rammed earth in sub-tropical, tropical and temperate climates of Australia using design data of the building fabric and glazing. Methodology - To improve energy performance of this building project, thermal simulation and comprehensive simulated data analysis were conducted, using BERSPro and according to the NatHERS Technical Note. This includes detailed analysis of heating and cooling energy (MJ/m2). Different constructions, including rammed earth wall, lightweight wall and heavy weight wall were used as building fabrics to achieve a cost effective, energy efficient and sustainable solution Results- Thermal performance of rammed earth is similar to other constructions in sub-tropical and tropical climate. No insulation is required for a rammed earth built house in tropical climate for the proposed floor plan. However, it requires more insulation with rammed earth in external walls to achieve NCC-complaint 6 star rating in temperate climate. Key Findings / Implications – The research highlighted that the rammed earth in external walls of the proposed house achieved minimum 5 stars in sub-tropical climate and minimum 6 stars in tropi-cal climate without any changes of other building elements i.e. insulation, glazing, awning. On the other hand, rammed earth house in temperate climate didn’t achieve 6 stars without changing other building elements. Originality - Two research questions are highlighted in this study (a) What would be the thermal performance of the rammed earth compared to other constructions in these three climate zones (b) What are the changes required to any building element for energy performance improvement of this building project? A comparative study for a rammed earth house has not being conducted before this research in climate zones 1, 2 and 6 using the NatHERS Technical Note and BERSPro software.