  This is the consensus of a Workshop on "Matrix elements for Neutrinoless
Double Beta Decay" held at the IPPP Durham (UK). The aim of this workshop has
been to define a well planned, coherent strategy to reduce the errors on
nuclear matrix element calculations for double beta decay to a level of 30% by
performing the necessary measurements with currently existing and planned
facilities. These measurements should provide reliable input for the
theoretical calculations. The outcome of the workshop has been organised in
working packages. The consensus might act as a starting point for an
international coherent effort to achieve this goal.
