This paper presents findings of an environmental and economical life cycle assessment (LCA) of individual Irish residential building structural wall and roof assemblies. A study found embodied energy (EE) and embodied carbon (EC) to account for up to 27% and 34% of lifecycle energy usage and carbon emissions, respectively, for studied Irish residential dwellings. Building superstructure and roof were discovered to contain on average 56% and 60% of case study associated EE and EC, respectively.This research found little difference between typical timber frame and concrete block cavity wall systems employed in Ireland in terms of lifecycle energy, carbon emissions and economic costs. Analysis on roof systems demonstrated cost and environmental impacts of insulated and un-insulated ceiling and rafter roof systems.Resulting from building envelope LCA, this research highlights the need for designers to consider various lifecycle qualities when selecting building materials. By increasing demand for energy consuming materials, manufacturers will be forced to adopt more energy efficient production methods to satisfy selection standards.