Founded in 1967, the Institut Laue-Langevin (ILL) is an international research centre at the leading edge of neutron science and technology. As a central facility, the ILL provides access to instruments that use low-energy neutrons of unequalled quality and breadth to a community of many thousands of researchers throughout Europe and beyond. The ILL has occupied this leading position for 35 years. In order to keep the ILL at the forefront of neutron science and to provide the best possible experimental facilities and support to its European users over the next two decades, the Institute needs to modernise its infrastructure and instrument suite. This is the scope of the proposed ILL20/20 upgrade programme, which can be summarised as follows: (i) improving neutron moderators and delivery systems; (ii) planning and prototyping new instruments and neutron technologies; (iii) strengthening the links with the European Synchrotron Radiation Facility (ESRF), creating partnerships for science and joint scientific facilities accessible to ILL and ESRF users; (iv) developing the site shared by the ILL, the European Molecular Biology Laboratory (EMBL) and the ESRF. This proposal aims at optimising the preparatory phase of this ambitious programme. The preparation of the upgrade will involve: (i) a benchmarking to enable a strategic decision to be taken on whether or not the ILL should focus on cold instruments ; (ii) feasibility studies, on challenging technical projects to renew the ILL's neutron moderators and delivery facilities, and on neutron scattering technologies; (iii) preparing the framework for a Partnership for Soft Condensed Matter; (iv) planning the development of the ILL/EMBL/ESRF site, including the resolution of the administrative issues.