A COMPARATIVE LIFE CYCLE ANALYSIS OF NEAR-ZERO ENERGY BUILDINGS WITH A FOCUS ON ENVELOPE INSULATION

ABSTRACT Near-zero energy buildings are known to have the potential to reduce energy consumption and consequent emissions. This article uses a life cycle analysis approach to evaluate the effects of using different insulating materials on the lifetime energy consumption of a near zero conditioning energy case study house in Wellington, New Zealand, by assessing the environmental impacts of a number of insulation options. The question addressed is whether using thick layers of insulation with high R-values in a building envelope is always a reliable approach to mitigating the impact of the built environment on the planet. The results show no significant difference between the environmental impacts of insulating the house using polyurethane and using no insulation in the first 28 years. The further discussion shows the energy profile used for processing the materials, construction and operating the buildings are not always the same, and this has a significant impact on the building’s environmental footprint. There needs to be a balance between both the value and profile of building operating and embodied energy. HIGHLIGHTS