Irish guidance for Integrated Biodiversity Impact Assessment provides a methodological approach for integrating impact assessment requirements, with regard to biodiversity, under EU and Irish legislation. Preparation of the guidance was supported by extensive consultation, including international and national surveys. These offered insights into the issues affecting the treatment of biodiversity in impact assessment practice as well as expert opinion on factors affecting and supporting the development of a more integrated and adaptive approach. This paper contrasts the international literature with the consultation feedback. Among other aspects, the results highlight the requirement for an improved application of evidence-based assessment techniques, continuity in monitoring, enhanced information exchange between scientists, assessors and proponents, as well as increased awareness amongst stakeholders for inclusion of appropriate biodiversity protection objectives and mitigation in final planning decisions. Comparative analysis of results indicates that current practice is characterized by limited information exchange and the use of in-house databases in assessments. A central spatial data repository is identified as key for quantitatively assessing (cumulative) effects through Geographic Information Systems, and thus supporting evidence-informed decision-making towards biodiversity conservation.