Here are some interesting blog posts by local authorities currently working to reduce energy use in their municipalities.
https://municipalpower.org/articles/how-dobrich-is-pioneering-the-energy-transition-in-bulgaria/
Blog post by (Radmila Jovanović of) Rijeka municipality (Croatia)
Blog post by Jon Gastañares and Iker Mardaras Larrañaga, Donostia-San Sebastián municipality
Interesting reports from leading think tanks:
Accelerating Building Decarbonization: Eight Attainable Policy Pathways To Net Zero Carbon Buildings For All, Renilde Becqué, Debbie Weyl, Emma Stewart, Eric Mackres, Luting Jin, And Xufei Shen, September 2019, https://wriorg.s3.amazonaws.com/s3fs-public/accelerating-building-decarbonization.pdf
Accelerating Building Efficiency Eight Actions for Urban Leaders by Jennifer Layke, Eric Mackres, Sifan Liu, Nate Aden, Renilde Becqué, Peter Graham, Katrina Managan, Clay Nesler, Ksenia Petrichenko and Susan Mazur-Stommen, World Resources Institute, May 2016 https://www.wri.org/publication/accelerating-building-efficiency-actions-city-leaders
Boosting energy retrofits in condominiums, https://energy-cities.eu/publication/boosting-energy-retrofits-in-condominiums/
Cities heading towards 100% renewable energy by controlling their consumption, https://energy-cities.eu/publication/cities-heading-towards-100-renewable-energy-by-controlling-their-consumption/