Simulation-based evaluation of energy performance in adaptive reuse of historic buildings across different climatic zones of Sri Lanka

Abstract

Adaptive reuse involves reusing historical structures without demolishing or reconstructing while preserving cultural and heritage values. In Sri Lanka, colonial-era buildings have been converted to modern purposes; their post-reuse energy performance remains measured. This study evaluates the impact of adaptive reuse on energy performance across three climatic zones in Sri Lanka, Jaffna (dry), Galle (intermediate) and Nuwara Eliya (wet) using Autodesk Revit 2025 Insight simulation. It aims to (a) Analyse architectural, material and functional changes (b) Quantify Energy use intensity (EUI), and (c) Propose strategies to maximize energy efficiency without compromising heritage integrity. Field data were modelled for pre- and post-modification phases to analyse EUI and end-use components (cooling, lighting and equipment). Comparative simulations generated retrofit recommendations. Results indicate EUI increased in adaptive-reuse buildings. In Jaffna EUI increased from 29.96 to 78.24 kWh/m²•year, and reduced to 42.54 kWh/m²•year after retrofit. In Galle, EUI increased from 28.87 to 67.72 kWh/m²•year, and decreased to 38.5 kWh/m²•year after retrofitting. In Nuwara Eliya, the EUI increased from 22.90 to 39.83 kWh/m²•year, and reduced to 30.5 kWh/m²•year after retrofit. The difference between the pre- and post-modification EUI was highest in the dry-zone case, followed by the intermediate zone, while the wet-zone case exhibited the lowest increase, due to climatic conditions, material replacement and purpose of the building. The findings show that poorly designed adaptive reuse, particularly enclosed spaces and light partitions, can increase cooling-related energy demand by 30-50% in dry and intermediate regions. Energy-efficient retrofit strategies can reduce energy consumption in such buildings.