Buildings with a longer life
Four engineering case studies in reuse, energy and material efficiency. Each reported result is attached to its measurement boundary. These are project-team accounts, not a sustainability league table.
| Project | Approach | Reported result | What it measures |
|---|---|---|---|
| Empire State Building ↗New York City, United States | Operational energy | 38%Reported energy-use reduction | Owner reports the retrofit reduction was validated and exceeded annually since 2010. This is energy use, not whole-life carbon. |
| Quay Quarter Tower ↗Sydney, Australia | Structural reuse | 65%Original floorplates and structure retained | Arup report narrative. This is a retention measure, not an energy-saving percentage. |
| 1 Triton Square ↗London, United Kingdom | Facade and material reuse | 40,000 tonnesReported carbon saving | Arup comparison with a typical new build. The public page uses ‘carbon’ without a complete lifecycle-module breakdown. |
| 8 Bishopsgate ↗London, United Kingdom | Structural material efficiency | 25%Reported steel-weight reduction | Arup comparison from individually optimising structural elements rather than grouped sizing. Not a whole-building carbon reduction. |
Before comparing carbon claims
Check whether the number describes energy or emissions, new construction or operation, one component or the whole building, and an estimate or monitored performance. An avoided-emissions claim also needs a clearly defined alternative. Raw tonnages cannot compare the efficiency of buildings with different sizes and uses.
The collection includes useful retrofit precedents outside the height ranking. Sources are linked on each case page; the site has not independently audited their calculations.
Read the engineering blog ↗ · Compare sourced building measurements ↗