Lithuania’s Educational Building Stock: Energy Performance, Data Gaps and Renovation Screening

National building registers can provide complete stock coverage, but missing energy performance data constrain renovation prioritisation. This study assessed all 4736 building objects officially registered for educational purposes across all 60 Lithuanian municipalities (8.77 million m²), using registry data, policy documents and exploratory responses from five municipalities. Overall, 91.8% of buildings were completed before 1991, and 96.2% were at least 20 years old. Official energy performance certificates were available for 2075 buildings (43.8%), and positive calculated heating demand values for 36.5%. Analytical proxy categories for uncertified buildings increased screening coverage to 100%. Validation against EPCs yielded 49.8% exact agreement, 82.8% agreement within one harmonised category and a linearly weighted Cohen’s κ of 0.243. The proxy classified 99.2% of buildings with official classes D–G as ≤D, but its specificity for retaining C-or-better buildings was 18.3%, demonstrating a trade-off between coverage and certainty. The broad D-or-lower screening group contained 3534 buildings; restricting it to those with registry-based physical depreciation of at least 40% and no recorded intervention completion identified 536 candidates for further assessment. Registry proxies can support transparent national screening and identify certification needs but cannot replace official EPCs or establish individual rankings under the Energy Performance of Buildings Directive.