The need for a unified appraisal framework for biomass and bioenergy has been extensively discussed in literature. It is emphasized that a working unified appraisal framework can essentially improve bioenergy policymaking by offering a structured and transparent approach to tackle the bioenergy trilemma and to work out whether or not a certain biomass conversion technology or system should be implemented (always in direct comparison to others). Further, such an approach could be used to better examine the interdependencies of the single elements of the triple bottom line of sustainability (economy, environment, society). This also would lead to the improvement of existing and future policies and would give bioenergy a better foundation within the ethical debate by transparently showing the trade-offs between economy, environment and society. This paper drafts a unified appraisal framework for biomass conversion systems that integrates different approaches on the data, impact and decision making level. On the bottom line the proposed architecture in total addresses all relevant requirements from literature and fits well into the valuable work that has been done previously. (C) 2015 Elsevier Ltd. All rights reserved.