Impact Assessment (IA) has the potential for delivering more sustainable development as well asenhancing the effectiveness and efficiency of decision making. Policies aiming at sustainabledevelopment need a solid foundation trough IA using a variety of IA tools. However, existing researchpoints out that the full potential of IA is not being realised. Many tools to support IA have beendeveloped, but are not yet being fully employed by policy makers. These missed opportunities aresymptomatic of a large and deep gap between the two broad communities of IA researchers and IApractitioners. Practitioners tend to look for tools that are simple and transparent while the researchersare more interested in the sophistication and innovative aspects of assessment tools. The main purposeof LIAISE was to identify and exploit opportunities to bridge between these two communities in a way thatleads to an enhanced use of IA tools in policy making. Its centrepiece was  a shared toolbox -simultaneously accessible and useful for policy makers as well as for the research community. TheLIAISE consortium did:· United the multi-disciplinary competences of a core of large European institutes, that in turnconsolidate the expertise from large FP6 projects such as SEAMLESS, SENSOR, MATISSE,Sustainability A Test, IQ Tools and EVIA;· Combined researchers that analyse current policy needs and link them in innovative ways (i.e.targeted, co-designed and co-produced IA ‘test cases’) to those who maintain existing and arepresently improving existing and developing new tools;· Developed a roadmap towards a virtual centre of excellence on IA, that operates as the durablehub of existing academic and practitioner networks relevant to the themes of the NoE;· Maintained the flexibility to support ‘real life’ IA processes, informed by a structured dialogue withthe IA user community, represented by a high level Policy Advisory Board;· Developed a business plan to ensure durable operation, scientific credibility and efficient usability ofthe shared toolbox, also in the post-project period.As a result of the project, the following outputs were reached:· A shared toolbox: a durable and flexible infrastructure to support IA with improved tools;· A continuously updated shared research agenda fed from scientists of different disciplines andpractitioners;· Capacity building and training components to spread the results of research activities to targetgroups in communities of IA users and IA researchers;· A virtual centre of excellence: an internationally visible, integrated and interdisciplinary scientificcommunity providing excellent and applicable research in support of IA.