By analysing the full life cycle of building service systems, from raw material extraction and manufacturing through installation, operation, maintenance, and final disposal, a comprehensive picture of their true environmental cost is built.
The material composition of technical systems is analysed in great detail, combining digital methods with expert knowledge to establish a robust framework for decision-making regarding existing systems, such as whether to reuse, recycle, or dispose of them.
The HIL Building as a Living Laboratory
Looking back at the 50 years that the HIL building has been in use by the members of ETH, many of its technical components have reached or exceeded their expected service life, and numerous systems have already undergone replacement. This accumulated history of ageing, failure, and renewal makes the HIL a complex and interesting case study for examining end-of-life scenarios and the environmental consequences of the decisions made around them.
The Carbon Impact of Technical Building Components
Technical building components, including heating, ventilation, air conditioning, electrical installations, and plumbing, represent a significant and frequently underestimated share of a building’s total carbon footprint. Unlike the primary structure, these systems are replaced multiple times over a building’s lifetime. Optimising decisions around these systems therefore has an outsized impact on the overall environmental performance of a building across its full lifetime.
Supporting Informed Decision-Making
A core strength of life cycle assessment is its ability to inform complex decisions that go beyond simple cost calculations. LCA methodology guides stakeholders, including building owners, facility managers, and engineers, through critical questions such as whether to replace or retain existing systems. Not every ageing system warrants immediate replacement. Factors such as remaining service life, energy performance, and embodied carbon are all weighed in this assessment.
When replacement is justified, LCA helps identify the most environmentally sound alternative by comparing candidate systems across multiple impact categories, including global warming potential, embodied energy, and resource depletion, rather than optimising for energy efficiency alone. Timing also matters: a phased upgrade strategy may deliver greater environmental savings than a full system overhaul, particularly when components have differing service lifespans.
