Households in the private rented sector (i.e., households renting properties at a market rate from a private landlord), and especially those of lower income, face far more energy poverty issues than the general population, meaning that they are often unable to afford socially and materially required levels of energy services. In this context, energy efficiency policies are of the outmost importance as they can improve households' living conditions and contribute to the alleviation of energy poverty. Nevertheless, when it comes to the private rented sector across Europe, implementing such policies is hindered by several barriers. Our article sheds light on structural factors that serve as barriers to, and solutions for, the implementation of energy efficiency policies in the private rented sector across Europe. Our approach is twofold: first, an in-depth desk research is performed to identify financial, social, political/regulatory, and technical barriers and solutions. Literature findings are then supplemented and validated by a European-wide survey, eliciting knowledge embedded in 64 relevant stakeholders and field experts. Our findings indicate that although financial barriers are always of the essence, a holistic assessment of barriers is required, as there is a lack of awareness about policies that could improve tenants' living conditions. They also provide possible solutions that governmental bodies at all levels and other organisations could implement to improve energy efficiency and tackle energy poverty. Overall, our work suggests key implications, which, if acted upon, could accelerate the deployment of energy efficiency policies in the private rented sector across Europe.