In Slovenia typical residential buildings from 1946 to 1980 have either masonry or reinforcement concrete structure. The envelopes built before 70-ties are without thermal insulation with double glazed box windows; but in 70-ties early thermal insulation materials were introduced. Nowadays, these buildings offer significant energy saving potential and often need repair because of inadequate maintenance. Since Slovenia is an earthquake prone zone interventions in envelopes in many cases comprise also additional strengthening. Recently, national regulation (2002) imposed some obligatory measures at envelope refurbishment, which are supported by subsidies for energy efficiency. Different technical solutions for envelope insulation improvement are common in Slovenia, but most frequently the external thermal insulation system with thin layer plaster is used, accompanied with multi-chamber PVC windows with low-e double glazing. In this paper the impacts of technical solutions in standard envelopes are discussed from technical, functional, social, economical and environmental aspects. The refurbishment case study reflects the contemporary approach to refurbishment.