RETROFIT-LAT: A comprehensive dataset for energy efficiency investments in Latvia

<ns3:p> This article presents RETROFIT-LAT: a collection of data from 1010 residential building projects, funded by the Republic of Latvia’s Environmental Investment Fund (LEIF). The first dataset analyses the energy performance and sustainability of buildings before and after retrofitting actions, including their energy consumption, <ns3:italic>CO</ns3:italic> <ns3:sub>2</ns3:sub> emissions, and energy classes. It spans projects implemented from 1870 to 2022, covering various building types and regions, with data on their energy use, heat loss coefficients, and both renewable and non-renewable energy contributions. The second dataset focuses on photovoltaic (solar panel) installations as part of energy efficiency measures. It documents electricity consumption, rimary energy use before and after installation, inverter power, and reductions in <ns3:italic>CO</ns3:italic> <ns3:sub>2</ns3:sub> emissions. Such a collection could offer a valuable foundation for developing machine learning models to evaluate and predict the impacts of retrofitting and solar panel installations on energy efficiency and sustainability. It could also be particularly relevant for researchers and policymakers who evaluate the effectiveness of energy-saving measures or planning similar interventions in other contexts. </ns3:p>