Papers 1 The challenge of refurbishing recently built apartments. A life cycle perspective Patxi Hernandez UCD Energy Research Group, School of Architecture, Landscape & Civil Engineering University College Dublin, Richview, Belfield, Dublin 4, Ireland. patxihi@gmail.com Stephen Cavanagh Gerry Cahill Architects, Dublin 4, Ireland Stephen@gca.ie Vivienne Brophy, School of Architecture, Landscape & Civil Engineering, University College Dublin Vivienne.brophy@ucd.ie Julie Futcher School of Architecture, Landscape & Civil Engineering, University College Dublin julie@climate22.com Zsuzsa Szalay UCD Energy Research Group, School of Architecture, Landscape & Civil Engineering Zsuzsa.szalay@ucd.ie Paul Kenny School of Architecture, Landscape & Civil Engineering, University College Dublin Paul.kenny@ucd.ie ABSTRACT Some countries in Europe have experience an unprecedented amount of building construction over the past 10 to 15 years. In countries such as Ireland, around 33% of the housing stock is less than 10 years old, with different constructions standards reflecting the evolving building regulations, which have been upgraded in 2002, 2005, and 2008. These buildings typically offer fewer options for cost‐effective improvement than older buildings, while still having a medium to high energy use and a long expected life, meaning a high long term impact which should be tackled as soon as possible. A neighbourhood in North Dublin, Ireland, constructed to comply with Building Regulations from 2005 is taken as a case study for this analysis. Different options for refurbishment are considered, and an analysis is presented based on dynamic simulation and life cycle energy analysis, using the Net Energy Ratio as the analysis tool instead of more commonly used economic indicators. This paper discusses best possible approaches to reduce life cycle energy use in recently constructed buildings including building envelope refurbishment, materials selection, systems integration, and influence on user’s behaviour. Keywords : building refurbishment, building retrofit , energy renovation, net energy ratio, life cycle energy analysis