An alternative approach to electronic structure calculations based on numerical methods from multiscale analysis, is suggested. We are aiming towards a local description of electron correlations using a wavelet basis adapted to the various length and energy scales of the physical processes involved. Taking a product ansatz for the wavefunction Y = F F, where F corresponds to a given mean-field solution, we approximate the correlation factor F in terms of hyperbolic wavelets. Such kind of wavelets are adjusted to higher dimensional problems and can be combined with adaptive nonlocal approximation schemes in the region of the inter-electron cusps. Necessary extensions for large systems, with improved scaling behavior, are proposed.