Post-Retrofit Performance Assessment of Administrative Building: Energy, Comfort, and Carbon Emissions

Retrofitting existing buildings for improved energy performance is increasingly recognized as a cost-effective and sustainable strategy to reduce energy consumption and greenhouse gas emissions, particularly in regions with intensive cooling demands (Al-Tamimi, 2022; Alrashed & Asif, 2015). This study presents a detailed, three-year post-retrofit performance evaluation of a government administrative complex located in Riyadh, Saudi Arabia. The retrofit intervention involved three buildings totalling 45,597 m² and included a suite of energy saving measures (ESMs) such as chilled water system optimization, packaged air-conditioning unit upgrades, and advanced lighting controls, all integrated through a centralized building management system (BMS) (Al-Mofeez & Al-Sallal, 2017). The measurement and verification (M&V) process was conducted in accordance with the International Performance Measurement and Verification Protocol (IPMVP), employing both Options A and B to assess system-level and whole-building impacts. The facility’s baseline energy consumption was established at 6.43 GWh annually, with a guaranteed savings commitment of 1.86 GWh (28.89%). Across the three-year performance period, actual energy savings consistently exceeded projections: 2.02 GWh (31.7%) in Year 1, 1.95 GWh (31.12%) in Year 2, and 2.01 GWh (31.59%) in Year 3. These savings were achieved without the need for non-routine adjustments, reflecting the reliability and persistence of the retrofit measures. Cumulatively, the project yielded nearly 6.0 GWh in energy savings and substantial economic benefits, with annual utility cost reductions ranging between SAR 600,000 and 650,000 (Al-Mofeez & Al-Sallal, 2019). The results confirm the technical and financial viability of performance-based retrofit projects in hot-climate institutional buildings, while also highlighting the effectiveness of a robust M&V framework (Krarti & Ihm, 2016; Al-Shehri & Al-Homoud, 2005). This study contributes practical evidence to support policy and investment decisions in energy efficiency programs across the public sector, particularly in high-growth, climate-stressed regions.