What is zoning? Spain's general plans and Japan's national zoning explained

Zoning is the rulebook that says what can be built on each plot of land: a home, a shop, an office, a workshop, how much floor space and how tall. Every city in Europe has one in some form. In Spain it lives in each municipality's general urban plan, the plan general de ordenación urbana or PGOU. Japan does it very differently, with a short national menu of zones, and the comparison is one of the most useful things Spain can study in a housing crisis. M. Nolan Gray's Arbitrary Lines and Alain Bertaud's Order without Design are the two books behind this piece.

How it works in Spain

A Spanish general plan makes two decisions in sequence. The first is clasificación, the classification of land. Every square metre of the municipality goes into a broad class, usually urban land, developable land (urbanizable) or non-developable land, and the class sets the owner's rights and duties. The details come from regional law, since planning has belonged to the autonomous communities since the 1990s; our explainer on the Land Law tells that story. State law sits on top with its own two basic situations, rural and urbanised land, in article 21 of the 2015 consolidated Land Law.

The second decision is calificación, which is what an English speaker would recognise as zoning proper. The plan assigns each area its uses (residential, industrial, tertiary, public facilities, green space) and their intensity, usually expressed as edificabilidad, the square metres of floor space allowed per square metre of land. Local ordinances then fix heights, setbacks, plot sizes and building types, often with a different ordinance code for each kind of block.

The plan also does things a market will never do by itself. It sets aside land for parks, schools and health centres, and the Land Law obliges landowners in development schemes to hand the council a share of the buildability, between 5% and 15% as a general rule. Since the 2023 housing law, article 20 requires plans to reserve land for at least 40% of the residential buildability in new urban extensions, and 20% in urban renewal, for housing under some form of public protection with a capped sale price or rent. Regional law can lower or waive the reserve only exceptionally.

Then comes the slow part. Making a general plan is so complex that, as the Ministry of Public Works put it in 2018, it can last six or seven years, or longer. And once approved, it is fragile. A plan counts as a regulation, so a formal or material defect in any section has meant the nullity of the whole plan, with no chance to correct it. The city goes back to its previous plan, usually out of date, and starts again. The ministry said the problem affected cities in practically every region. The ministry proposed partial nullity that year, and as our Land Law explainer recounts, later versions of the same fix have been tabled and voted down.

How it works in Japan

Japan writes zoning into national law. The Ministry of Land, Infrastructure, Transport and Tourism describes twelve land-use zones, grouped into residential, commercial and industrial, each with its list of the building uses allowed. Cities draw their maps using those zones, and the ministry's own brochure says the zone regulations apply uniformly nationwide. A municipality can tighten or relax them in a special district through a local bylaw, and it can add district plans with detailed rules on local roads, small parks or building design, with residents able to send written objections before the plan goes to a planning council.

The logic of the zones is what makes them so permissive. A 2014 post on the blog Urban Kchoze, one of the best-known explainers in English, describes each zone as tolerating uses up to a maximum level of nuisance. Anything quieter is allowed too. So homes are allowed in the commercial zones and in most industrial ones, and only the exclusively industrial zone keeps housing out. Most zones end up mixed. Japan also draws no line between types of home: a detached house and a block of studio flats are both simply residential, and density is managed with floor-area and coverage limits that cities pick from a fixed set of values, plus national rules on height, slant planes and sunlight.

The national government owns the rulebook. Alan Durning of the Sightline Institute recounts how it grew from three zones in 1919 to eight in 1968 and twelve in 1992, and how the Diet can change it for 126 million people by a majority vote. Since 1999 private consultants can authorise building permits. Compare that with more than 22,000 American cities and counties writing their own codes, which is the world Gray describes in Arbitrary Lines.

The results show in the housing figures Durning collected. Tokyo Prefecture, with 13.5 million residents in 2018, built 145,000 new homes that year, and it routinely builds more than the whole of California. It has tripled its housing stock in fifty years, and its prices and rents have, in Durning's phrase, "barely budged since 2000".

What Spain can take from both

Gray's case, as H. Shelton Weeks summarises it in his 2023 review, is that zoning began in American cities in 1916 with exclusionary goals, that rules like minimum lot sizes and parking requirements raise costs, that slow, uncertain approvals add more, and that planning should concentrate on real nuisances. He would go as far as abolition, with Houston as his example, and sees limits on local control as the key to reform. Bertaud, whose book we explained here, arrives somewhere close from the planner's side: build the infrastructure, watch land prices and densities, and regulate clear negative effects.

Japan shows that a country can keep zoning and still get homes built. That is where the radical-centre position sits. Spain should keep what its planning tradition does well, a public say over green space, schools and services and a guaranteed share of land for protected housing, because those are common goods nobody else will secure. It should borrow Japan's predictability: rules simple enough that a compliant project gets built by right. And it should change who writes the menu. The state and the regions could agree a short catalogue of simple, cumulative zones, with mixed use as the normal case and housing allowed in nearly all of them. Councils would then spend their time choosing zones for their map, reserving land for protected homes and planning transport, and a plan built from a common catalogue would be quick to approve and easy to correct when a judge finds a fault in one corner. Our piece on developable land shows what that land is waiting for.