A Demand Controlled Hybrid Ventilation System is a two-mode system using natural forces as long as possible and electric fans only if necessary. Sensor technologies are used to establish the exact required airflow for indoor air quality and thermal comfort to a minimal energy demand. A large part of the Dutch dwellings are foreseen with a ventilation system consisting of natural supply with mechanical exhaust. Fan power for these systems typically is 30 - 40 W (Specific Fan Power 0.7 - 1.0 kW/(m3/s)). Small improvements lead to a laboratory reference of 21 W. In the EU TIP-VENT project improvements on ductwork and fan have resulted in a fan power of 7 W (SFP 0.17 kW/(m3/s)) A further step forward in energy reduction is now realized within the RESHYVENT project. In this project a Dutch industrial consortium together with TNO develops a demand controlled hybrid ventilation systems for residential buildings. The system consists of self-regulating inlets and vents, round 225 mm ductwork, a DC fan and an optimized roof outlet. A CO2 sensor based control system will adjust the ventilation to required airflows with respect to indoor air quality. Target fan power is lower than 2 W (SFP < 0.04 kW/(m3/s)).