Owners often assume a site is fully worked before it is. The capacity that remains is rarely dramatic, but on a constrained urban plot even a modest gain changes the investment case.

The first place to look is vertical: services routed through occupied floor area, plant rooms sized for equipment that has since been replaced, and voids retained from an earlier layout.

The second is regulatory. Planning envelopes are frequently more generous than the built form that sits inside them, particularly on parcels developed before the current framework.

The remaining three are operational — circulation efficiency, storage consolidation and yard sequencing — and they tend to be found by walking the site at its busiest hour rather than by reading its drawings.