Integrated Regression and Cluster Analysis for Cost Benefit Evaluation of Energy Retrofit Interventions in Hellenic Schools

School of Applied Arts and Sustainable Design, Hellenic Open University, 26335, Patras, Greece

Abstract

This study introduces and explains a methodology that integrates regression and cluster analysis of Energy Performance Certificates data to evaluate the cost effectiveness of energy retrofit measures in Greek school buildings. These interventions have been supported by European funds and are scheduled to be implemented in schools across different climatic zones in accordance with the national Regulation of Energy Performance. The analysis first identified which architectural, economic and energy-related variables most significantly affect the cost-benefit ratio of interventions in schools located in warm and cold climatic zones. Cluster analysis then classified the school buildings into two homogeneous groups, one with larger, compact structures that initially exhibited reduced energy demands but required significant capital investment to achieve significant retrofit results and the other consisting of smaller, less compact buildings that demonstrated significant retrofit potential and energy savings related to the invested resources, despite their higher initial energy consumption. The study also identified representative building typologies to guide the optimization of retrofit strategies. The results indicate that balanced investments and targeted energy measures can lead to more sustainable and cost-effective educational buildings.