This document presents a study of the energetic-environmental behaviour in an apartments building in La Plata, which has a mild, warm and humid climate. The detailed analysis started with two audited apartments. The results were transferred to the whole apartments building for its global analysis. As regards the methodology used, the method “Audit-CAD” was used, which allows to measure the thermal and energetic behaviour of the building monthly by means of incorporating the audited information when the formal and energetic indicators are determined. Passive strategies for a redesign of low energy are also suggested (green-retrofit) where concepts of Environmentally Conscious Design (ECD)are involved in order to promote low energetic consumption. The fulfillment of Argentinian standards is verified to ensure its energetic efficacy. For this purpose, “U” values (coefficient of heat transmission) for walls, roofs and openings,superior to the top level of the IRAM standard 11605 about building thermal conditioning are suggested. Subsequently,the accomplishment of the IRAM standard 11900 about labelling energetic efficiency of heat for buildings is verified.Facultad de Arquitectura y Urbanismo