The ISOL-SRS project is a major component of a wider European initiative that will exploit the upgraded radioactive ion beam accelerator HIE-ISOLDE at CERN and, although still currently under discussion, the heavy ion storage ring CRYRING at GSI/FAIR. The UK collaboration is leading the development and construction of advanced, innovative detector systems for experiments at these facilities that will deliver a vast range of isotopes at energies ideal for studies of nuclear phenomena. It will provide unrivalled opportunities for measuring key reactions and properties of nuclei relevant for nuclear astrophysical processes, and measuring single-particle, collective, and ground-state properties of the nucleus essential to the understanding of the interactions between nucleons in exotic nuclei, at both the precision and intensity frontiers. The main goal of the project is to build a spectrometer system for the measurement of charged-particle reaction products both in-ring and external to the ring, each employing high granularity silicon-detector systems. The two detector systems will enable the whole range of radioactive nuclei accelerated by HIE-ISOLDE and possibly GSI/FAIR to be studied with unsurpassed energy resolution and sensitivity, taking advantage of the superior properties of their radioactive beams. Both in-ring and external components of the spectrometer should achieve a final state resolution approaching 20 keV FWHM for inverse binary reactions such as d(A,p)B and approaching 50 keV FWHM for Coulomb excitation by carbon targets.