Shikang Wen / 温世康

Shikang Wen / 温世康

Research in building energy, computational design, and intelligent built environments.

Building retrofits in a high-density campus

Published research Apr 2025

Overview

This project assessed how two existing campus office buildings in Hong Kong could reduce operational carbon emissions by 50% by 2035 while maintaining practical investment pathways.

Campus site plan locating the two case-study buildings, with axonometric models and their area, function, construction year, height, and window-to-wall ratio.
The two case-study buildings on the PolyU campus: an administrative office tower and an academic office block.

Method

EnergyPlus simulation was integrated with life-cycle cost analysis for two campus office buildings. Strategies addressing occupant demand, renewable generation, lighting, windows, and mechanical ventilation and air-conditioning systems were evaluated individually and in combined retrofit packages.

Bar charts of annual energy use intensity by end use for the two buildings, split into lighting, equipment, AC plant, and air side.
Baseline energy use intensity by end use, calibrated against metered consumption.

Key findings

The combined strategies reduced operational carbon emissions by 50.1% and 50.5% in the two case-study buildings. Chiller upgrades delivered the largest energy savings, followed by LED lighting and renewable-energy systems. Shallow retrofits and LED systems offered the shortest payback periods, while envelope measures requiring exterior scaffolding generally had longer paybacks.

Stacked bar charts comparing original, shallow-retrofit, and combined shallow-and-deep-retrofit energy use for both buildings, showing reductions of 50.1 and 50.5 percent.
Energy use under the original, shallow, and combined retrofit packages for both buildings.
Paired bar charts of net present value and payback period for each retrofit scenario in both buildings.
Net present value and payback period for each retrofit scenario.

Contribution

Conceptualization, data curation, methodology, software, visualization, and original-draft writing.