For anyone who owns a plot in neighborhoods like Vila Mariana, Perdizes or Mooca, what the law allows to be built on that lot sets the value of the property and the fate of entire projects. That is the calculation that the courts have now upended. The Órgão Especial, the top body of the São Paulo State Court of Justice (TJ-SP), ruled on Wednesday (26) that the zoning map from the second stage of the revision of the city's Lei de Zoneamento, the municipal law that defines what can be built on each block, is unconstitutional. The map had been sanctioned in July 2024 by Mayor Ricardo Nunes (MDB). According to g1, the justices found that the changes entered the law without sufficient technical planning and public participation, distorting the original proposal, which was only meant to correct specific errors in the map.

In practice, the decision affects at least 15 points across the city whose urban classification was changed through amendments by city councilors in July 2024. They include plots that gained incentives for high-rise construction, areas earmarked for social housing that changed use, and lots reclassified for commercial, mixed and institutional purposes in districts such as Vila Mariana, Perdizes, Santo Amaro, Mooca, Ipiranga, Vila Sônia, Capela do Socorro and Tucuruvi. The full reach is still unknown, because part of the changes went straight onto the zoning map without a detailed description in the law's text.

What changes now, and for whom

• Until the judgment record is published, expected in the coming weeks: all permits, certificates, approvals and projects filed under the current rules remain valid, a protection known in Brazil as "direito de protocolo" (filing right).
• After publication: anyone who files a project under the annulled rules takes on the legal risk. The warning came from the head of the Órgão Especial himself, Justice Francisco Loureiro, in the prevailing opinion.
• If the ruling is upheld after appeals: the July 2024 rules cease to apply and the January 2024 map returns.

Even so, nothing changes immediately. A decision by Justice Edson Fachin of the Supreme Federal Court (STF) keeps the effects of the unconstitutionality ruling suspended until the case becomes final, and both the city hall and the city council are studying appeals.

Who fixes the law

Fixing the problem falls to the mayor and the councilors. On Thursday (27), Nunes downplayed the impact and noted that the court struck down only Article 8, the one that changes the map, not the whole law. He added that if he identifies something "very important for the city" among the annulled points, he will send a new bill to the council to fix them. The city council said it received the decision "with respect", but maintains that both revision laws followed "full compliance with legal norms and the House's internal rules", and that its legal office will assess possible appeals after the judgment record is published.

It is worth noting what remains standing: the map sanctioned in January 2024, in the first stage of the revision, was upheld by the same court, which rejected the Public Prosecutor's Office arguments against it. According to a city hall document submitted to the court, that update had already reclassified 3,992 city blocks, about 6% of the total, expanding areas with incentives for vertical development.

In the real estate market, the mood is caution. Marcelo Kalil, a lawyer specialized in real estate law, summed up the builders' dilemma to g1:

"Once the judgment record is published, a developer who applies for a permit will be betting on the outcome of the case at the Supreme Court. If the STF upholds the unconstitutionality, the construction loses its legal basis."

The housing developers' union Secovi-SP and the Brazilian Association of Real Estate Developers (Abrainc) have not yet finished assessing the impacts. In a statement, Abrainc said it awaits the judgment record to evaluate "the measures needed to ensure legal certainty for developments". Urban policy consultant Gabriel Rostey argues that the modulation of effects does not remove the uncertainty, because the market works on long cycles: the price of a plot and the viability of a project depend on its construction potential. Researcher Bianca Tavolari, a law professor at FGV who followed the revision between 2023 and 2024, criticizes the process: she says public hearings were held without residents having access from the start to the map that would actually be voted on, and the final text was presented only hours before the vote. In her assessment, the ruling could set the standard for future urban revisions in the city.