For achieving the 2°C goal of the Paris climate protocol, decarbonization of the building sector, which accounts for about 50% of the primary energy consumption [7], is planned for 2050. With a current annual building refurbishment rate between 0,4 and 1,2% in the EU it will be impossible to reach this objective. For getting on track, efficient and particularly affordable solutions fulfilling future-proof requirements are needed. This paper introduces the concept of HVACC 4.0, which stands for Heating, Ventilation, Air Conditioning and Chilling. The system architecture differs from state of the art HVACR, where the R stands for Refrigeration, in at least three points: (1) The innovative thermal storage and collector concept allows to harvest and store "low temperature heat and cold" on a daily basis, (2) in heating applications, the disruptive refrigerant cycle allows to more than double the Coefficient of Performance (COP) compared to air-water heat pumps and (3) in cooling applications, the night-time harvesting of cold via unglazed PVT-collectors allows to boost the Energy Efficiency Ratio (EER) by a factor of >10 compared to split devices or cold water aggregates. HVACC 4.0 aims to provide a solution in form of an easy-to-install refurbishment kit. The design criteria for addressing the "4.0" in HVACC 4.0 have been (1) to exemplify the principle of "efficiency 1st", (2) to maximize the share of Renewable Energies (RE) on total energy consumption, (3) to allow serving next generation low temperature District Grids (DG) and (4) to allow "more sector coupling". As new and innovative RE sources with high collector yield, unglazed PVT-collectors (Photo Voltaic & Thermal) and thermally activated Sheet Pile Systems are discussed.