409: Crossing Tresholds A Zero Energy Demonstration House in Ireland

This paper presents a case study of the iLEEiD research and demonstration house, which is targeted to be one of Irelands first Zero Energy house. The house is currently under construction and due for completion in October 2008. The design philosophy behind the project attempts to integrate two often divergent schools within the environmental buildings movement, notably ultra low energy design and environmental impacts of materials. A particular focus of the study is to explore the threshold where ultra low energy design mandates a shift and transition to low impact materials, including low embodied energy and embodied carbon, with implications for the envelope design, material specification and construction in particular. This study includes a comparative analysis of embodied energy and embodied carbon for an experimental wall build up, examined against traditional cavity wall construction methods across a range of required U values / energy targets. In addition to demonstrating the technical possibility of achieving Zero net Energy it is hoped this project will provide useful data and stimulate debate concerning the need to move to an integrated and holistic sustainability paradigm in building design and construction