Who is allowed to know who owns the building

Before asking who owns a tower, ask whether anyone outside its owner is permitted to find out. Across the fourteen cities examined so far the answer ranges from "here is the whole register, free, as a file" to "not at any price" — and that difference is larger, and more consequential, than any difference between the buildings themselves.

The ladder

Every city page opens with the same four questions, because they decide what the rest of the page can contain: is ownership public, what does one search cost, is there a bulk file, and are sale prices published. The answers sort the cities into four rungs.

An open dataset names the owner. New York publishes 858,284 tax lots with an owner name attached, free and without a key, beside the assessed value, the floor area by use, the number of floors and the year built. Cook County publishes 2,686,086 sales with a price, a date, and both the buyer's and the seller's name. Miami-Dade goes one better in a way that matters: it publishes the owner's mailing address, which is how a numbered company becomes a recognisable one — a lot at 200 South Biscayne Boulevard resolves to Ponte Gadea, and a shopping centre whose owner mails to Indianapolis resolves to Simon Property Group. Dallas publishes owner names on 2.59 GB of county roll.

Public, but one paid search at a time. Most of the world sits here. Anyone may ask who owns a given address, and pay for the answer: £7 in England and Wales, €3.70 in the Netherlands — which returns the owner, the last sale price and the parcel size — NZ$8 in New Zealand, about S$5.25 in Singapore, and ¥140 in Japan, which asks neither for a reason nor for proof of identity and is on that measure the most open register in the world. Ontario is the expensive end of this rung: $37.10 per parcel register from 2 November 2026, with no value and no price included.

Only if you can prove you deserve it. Germany's Grundbuch is chargeable and conditional on demonstrating a legitimate interest under §12 of the Grundbuchordnung. Market research is not a legitimate interest. Italy is the same shape with a friendlier face: cadastral data are public to everyone and a search by person is free online — behind a national digital identity, which a foreign researcher cannot obtain, so the free route is closed and the paid counter route is not.

Not public at all. Dubai's title deeds are not a public register and there is no way to search by name. Abu Dhabi issues ownership as a certificate to the owner. California — a jurisdiction people assume is open — publishes no owner name at all: Los Angeles County's public parcel layer carries 92 fields across 2.4 million parcels with values on every one and an owner on none, and San Francisco's roll states that it contains "all legally disclosable information", the owner's name not being among it.

What follows from the rung

The rung determines what the research can say, and it shows on the page. Where an owner could not be established, the building says so and gives the reason — the register is closed, a paid search would answer it, the licence forbids naming, or the source would not open. Of the 109 buildings examined, 83 carry an established owner and 26 do not, and the 26 are not a backlog to be cleared but the finding itself.

It also determines where the answer comes from. On the open rung the register answers directly. On every other rung the answer has to come from a filing: a REIT's Schedule III property table, an Exhibit 21 subsidiary list, a pension fund's own disclosure, a dated press release on the acquirer's newsroom. This is more durable than it sounds, and the alternative is worse — owners' own websites rot fast. Brookfield rebranded to BGRE in July 2026 and its deep property URLs now redirect to a corporate page; Oxford's portfolio page renders "Fetching properties" with zeroed counters; Cadillac Fairview's news URLs 404. A filing from 2024 is still there.

Two traps worth naming

Open data is not the same as usable data. Owner names in these registers are raw strings with no entity resolution behind them. New York's file contains "SL GREEN REALTY CORP." and "SL GREEN PROPERTIES" as unrelated values, a search for one large family landlord's name also matches a private individual who happens to share it, and 8,241 lots read "UNAVAILABLE OWNER" or "NAME NOT ON FILE". Cook County's own documentation says the owner name is "only intermittently updated", its sale dates are truncated to the month, and its largest recorded sale — $930,000,117 — is plainly a keying error. Any claim about concentration has to be built on top of a normalisation step, and has to admit it.

A price is not a value. Every price on these pages is a number a document states, with the date it states — not an estimate of what the asset is worth now. Where a jurisdiction publishes no prices at all, that is said rather than filled in. Texas is the clean example: Dallas County will give you the owner of every parcel and, being a non-disclosure state, the price of none of them.

What this section will not do

Listing portals hold the prices people actually think of as market data, and their terms forbid taking them. Rightmove states it outright — "Rightmove prohibits the scraping of its content" — and Realtor.ca, Zillow, Domain and Idealista say the same in theirs. So none of it is taken. Where those firms publish an index or a research download, that is cited instead, which is both legal and more honest: an index is a measurement, and a scraped asking price is an aspiration.