Plot Size Decides Who Is Able To Build At All

The pattern of land ownership in a city sets who can build on it. Plot size, more than policy, decides whether a small builder or a large one is the plausible developer.

Fine grain and coarse grain behave differently

A street of narrow plots can be redeveloped one building at a time, by owners with modest capital, over a period during which the street keeps functioning.

A single large parcel must be developed as one project, which requires a party able to fund the whole thing and to carry the risk until it is complete.

Both routes produce buildings, but they produce them at different speeds, in different quantities and by different sets of people.

Fixed costs favour the large scheme

Planning applications, technical reports, legal work and finance arrangement have costs that do not scale down proportionally with the size of the scheme.

Spread across a large development those costs are trivial per unit. Spread across a handful of homes they are significant enough to change viability.

The effect is a threshold below which development is uneconomic regardless of demand, and that threshold rises as the requirements attached to permission grow.

Assembly changes the character of what follows

Combining small plots into a single site is often necessary to reach that threshold, and the assembly itself takes years and specialist capital.

Once assembled, the site is unlikely to be broken up again, because the value created by consolidation would be lost.

The grain of the city therefore coarsens over time in one direction only, and the variety that comes from many hands building separately does not return.

Large sites concentrate risk in fewer decisions

When a district is delivered by a single scheme, its success depends on that scheme's programme, funding and design being right.

A downturn stalls the whole area rather than one building, and the half-finished site sits idle because no smaller party has a plot to work on.

Dividing large sites into serviced parcels before disposal is the standard remedy, since it restores the possibility of several builders working in parallel.

Policy can restore grain deliberately

Some authorities set maximum plot widths, require frontages to be broken up, or dispose of public land in small lots with conditions on who may bid.

These measures accept a slower delivery rate in exchange for more participants and more varied output.

Where they are absent, the parcel map does the deciding, and it usually decides in favour of whoever can already write the largest cheque.