Decision makers recognize the importance of lifestyle changes in reaching low emission targets but how the abatement potential of changes in diets, mobility or housing compare to ambitious technical measures in the transition toward decarbonisation, is not yet well understood. The new simulation model EUCalc shows that changes in lifestyles to be associated with 20% of the total reductions in carbon emissions between 2020 and 2050 that are necessary for reaching net-zero. The impacts of lifestyle changes vary across sectors but there are significant benefits in all. Changes in travel behavior limit the rise in demand for electricity and material demand from the electrification of passenger transport. Adopting healthy diets reduces emissions substantially compared to intensifying agricultural practices and makes cropland available for conservation or bioenergy purposes. The trade-offs are therefore not between food and energy but between maintaining excess food consumption and having enough land for bioenergy crops. Moreover, results show that without the contribution from lifestyle changes, Europe is bound to rely on high risk, high cost carbon removal technologies for its net-zero ambitions. Neither technology nor lifestyle changes will be enough to achieve full decarbonisation alone by 2050, but changes in lifestyles are crucial and help reaching net-zero emissions sooner.