Although infilling of wetlands (legal and illegal) is commonplace, little is known about the spatio-temporal distribution of construction & demolition (C&D) waste infill sites at a local scale. This is of particular concern given the multiple functions of wetlands including, inter alia, habitat provision, flood control and water storage. This case study from an Irish local authority quantifies, for the first time, the use of wetland habitats for C&D waste infilling in addition to identifying patterns of C&D waste site distribution and recording issues of non-compliance. We found that C&D waste cover on study sites grew from an estimated <10 ha in 1995 to >200 ha in 2010 within which time rapid economic growth occurred. Wet grasslands and peatlands were the most commonly infilled habitats, particularly near urban areas and adjacent to major roads. Of greater concern was that over 40% of C&D waste sites granted permits were located within one kilometre of Special Areas of Conservation (EU Habitats Directive) and 54% were located on extremely vulnerable aquifers. Conditions attached to infilling permits were frequently broken and commonly occurring illegal infilling sites had similar distribution patterns to the legal sites. Providing local authorities with sufficient resources to effectively police these sites in combination with examining alternative uses for C&D waste (e.g. recycling), are likely to be the most effective ways of dealing with these issues. More rigorous ecological investigations of proposed infilling sites prior to granting of permits would also limit the number of wetlands affected by infilling. (C) 2015 Elsevier Ltd. All rights reserved.