Press · As of 6 November 2026

Housing in Austria, recalculated.

wohnwahn.at is a free, independent property search for all of Austria. In the federal state capitals and their surroundings it shows for every address what a listing leaves out: heat, noise, flooding, sunlight and real travel times, each with its source. Two private individuals run it without investors or commissions; their data videos had reached around 2.2 million views by 4 November.

Julien El-Bahy and Christoph Dernberger. There is no press office. We usually answer queries the same day.

Call +43 664 18 17 680 Send an email

Stills from three data videos. “Vienna by the sea” and “Austria under ice” are painted with AI, based on our terrain and map data.

Data videos

2.2 mviews by 4 November 2026, according to the statistics of Instagram, TikTok and YouTube

Under the title “Austria, recalculated”, short films made from open data and historical sources have appeared since October 2026. Each has its own page with the film and every source, and five of them have a map where your readers can enter their own address.

All data videos →

The channels: Instagram · TikTok · YouTube

We are happy to send stills and full-resolution clips. Some scenes contain Google map imagery, images painted with AI or an AI voice; which ones is stated on the video’s page. For a television piece we go through the scenes with you in advance.

How we build: with AI

wohnwahn is built by two people, without employees or investors. An AI writes most of the code. The founders decide what gets built, and to keep the AI’s mistakes from slipping in, the site’s rules are guarded by automatic checks.

As of 5 November 2026, counted in the code archive

3,790

changes to the code since 23 June 2026

2,608

of them co-authored by Claude (Anthropic)

209

automatic checks

185

sabotage counter-tests

Programming: Claude by Anthropic writes the code to Julien El-Bahy’s specifications, around 320,000 lines for the website and data pipelines. Every change is traceable in the code archive.
Checking: Key rules such as “no figure without a source” or “the exact address stays protected” have an automatic guard. Every guard is deliberately broken to see whether it fires: those are the sabotage counter-tests.
In the search: AI understands free text (“quiet, 40 minutes to the centre”), checks new listings for data errors, reads floor plans and shortens and translates listing texts without adding anything; the original stays visible. Running it costs around 9 US dollars a month.
In the videos: Some views are painted with AI, from our own templates built on terrain and map data, and the voice is AI-generated. This is stated with every video.
What the AI does not do: It does not supply any figures about a location: heat, noise, flooding, travel times and sunlight come from official and open data and our own calculations, each with a source. And it does not bring in listings; those come from agents, developers and private owners.

The figures

Counted when this page was loaded, 6 November 2026

5,365

listings online

connected providers

regions with all location data

477

neighbourhood pages

Of these, 770 homes to rent and 3,598 to buy, 624 commercial units, 233 plots and 140 parking spaces. 68 per cent are in Vienna and its surroundings.

Vienna & surroundings · Graz & surroundings · Salzburg & surroundings · Linz & surroundings · St. Pölten & surroundings · Innsbruck & surroundings · Bregenz & the Rhine valley · Klagenfurt & surroundings · Eisenstadt & surroundings

Please quote the figures with their date. They describe the listings on wohnwahn.at, not the housing market.

The inventory week by week

Counted since 24 August 2026; there is no count before that. The vertical lines mark the days a region was added.

Vertical lines, newly added: Linz & surroundings (26 Aug) · St. Pölten & surroundings (28 Aug) · Innsbruck & surroundings (3 Sept) · Klagenfurt & surroundings (7 Sept) · Bregenz & the Rhine valley (10 Sept) · Eisenstadt & surroundings (12 Sept)

Listings online, week by week
Week	Listings online
24 August 2026	4,115
31 August 2026	4,132
7 September 2026	4,762
14 September 2026	4,682
21 September 2026	4,701
28 September 2026	4,570
5 October 2026	4,509
12 October 2026	4,548
19 October 2026	4,825
26 October 2026	4,786
2 November 2026	5,141

The same figures, machine-readable (JSON)

Story ideas

We combine the location data with our listings and analyse them for you, exclusively if you wish. You get the cut-off date, the denominator, the method and its limits. If the numbers do not support your thesis, we will tell you that too.

Housing and data

Heat and rent
How are the listings on wohnwahn and their prices spread across the officially overheated areas of Vienna and Graz?
The dark ground floor
How many hours of sunlight lie between the ground floor and the fourth floor, in June and in December?
Noise outside the window
What share of the flats on wohnwahn are at addresses the official noise map marks as exposed?
Promise and location
What a listing promises (“quiet”, “sunny”, “green”) and what the location data says about it.

Local news

Your district, recalculated
For local newsrooms we recalculate a district, a neighbourhood or a street in one of the state capitals, with the map as an image.
What was at your address?
Five data videos come with a map to link to: your readers enter their own address and see what used to be there.

Interview partners

Julien El-Bahy: Data and method: heat, noise and sunlight in the city, open government data, how the data videos are made and where AI comes in.
Christoph Dernberger: House hunting and the property market: what to look for in a location and what a listing gives away about it.

Our analyses describe the listings on wohnwahn.at, not the housing market; 68 per cent of them are currently in Vienna and its surroundings. Correct wording is “of the flats on wohnwahn.at”.

What wohnwahn shows for every address

Every figure states its source. Where nothing was measured, we say so instead of estimating.

Heat: Official urban climate maps in Vienna and Graz, otherwise a model built from Copernicus data. The origin is stated for every value.
Noise: Official noise maps under the EU Environmental Noise Directive, day and night. If a street is not mapped, it says so, not “quiet”.
Travel times: An in-house routing engine using the timetables of the transport associations and ÖBB, plus bike, car and walking. Real routes, not straight lines.
Price in context: We show whether a price is within the usual range, measured against similar listings in the same area, and what it was compared with. Where there is not enough to compare, there is no verdict.
Flooding: Flood areas for 30-, 100- and 300-year floods from the official maps of the federal and state governments.
Zoning: Land-use zoning from the states’ geodata services, per address, currently in seven of nine regions.
Green space and trees: Tree cover and green areas from Copernicus data and OpenStreetMap.
Sunlight: Hours of sunlight per floor and month, calculated on an in-house 3D model including neighbouring buildings and terrain.

Method and all sources →

The facts at a glance

Founded: June 2026, in Mödling near Vienna.
Operator: A private project by two founders, not a company, no employees. The media owner is Julien El-Bahy (disclosure in the imprint).
Funding: Self-funded. No investors, no commissions, no paid placements. Free for searchers and providers.
Listings: Agents and developers deliver via interfaces, private owners list directly on wohnwahn.at. Portals are not scraped.
Independence: wohnwahn belongs to its two founders. No agent, developer, portal or investor is involved. Julien El-Bahy is a Green Party member of the municipal council of Mödling; wohnwahn is separate from that, with no link to the municipality or the party.
Privacy: No Google Analytics, no advertising cookies. Without the provider’s consent the map shows only an approximate location.
Spelling: “wohnwahn” is written in lower case, including at the start of a sentence. The address is wohnwahn.at.
Regions: These are the days each region went live. Vienna went live first, on 28 June 2026; the others followed between 16 August and 12 September 2026. A region only goes live once all its location data has been calculated and checked.
All launch dates
28 June 2026Vienna & surroundings
16 August 2026Graz & surroundings
19 August 2026Salzburg & surroundings
26 August 2026Linz & surroundings
28 August 2026St. Pölten & surroundings
3 September 2026Innsbruck & surroundings
7 September 2026Klagenfurt & surroundings
10 September 2026Bregenz & the Rhine valley
12 September 2026Eisenstadt & surroundings

Quotes

You can use these quotes without asking, attributed by name. For radio and television we are happy to record a sound bite.

A listing shows you the flat, but not the location. We show both, even when the data contradicts the listing.

Julien El-Bahy, founder

You can change almost anything about a flat except its location. That is why the location is what you should know most about before you sign.

Christoph Dernberger, co-founder

Texts to copy

Free to use, shorten as you like.

One sentence

wohnwahn.at is a free, independent property search for all of Austria that shows heat, noise, flooding, sunlight and real travel times for every address in the federal state capitals and their surroundings, each with its source.

One paragraph

wohnwahn.at is a free, independent property search for all of Austria. In the federal state capitals and their surroundings it shows for every address the heat exposure (official in Vienna and Graz, otherwise from a Copernicus model), traffic noise from the official noise maps, flood zones, green space, real travel times by public transport, bike, car and on foot, and hours of sunlight per floor, each with its source. It has been run since June 2026 as a private project by Julien El-Bahy and Christoph Dernberger, without investors, commissions or paid placements.

In full

wohnwahn.at is a free, independent property search for all of Austria. In the federal state capitals and their surroundings it recalculates every address street by street: heat exposure, traffic noise from the official noise maps, flood zones, zoning, green space, hours of sunlight per floor from an in-house 3D model and real travel times from the timetables of the transport associations. Every figure carries its source, and where nothing was measured, it says so. Anyone who sets their priorities sees how well a home fits them (the “fit”), with reasons; without priorities there is no verdict, only facts. Agents and developers deliver their listings via interfaces, private owners list directly. Julien El-Bahy and Christoph Dernberger founded wohnwahn in Mödling in June 2026 as a private project without investors, commissions or paid placements. Under the title “Austria, recalculated” they also publish data videos on Instagram, TikTok and YouTube, which had reached around 2.2 million views by 4 November 2026.

Images

Free of charge for reporting about wohnwahn, credit “wohnwahn.at”. The map credit inside the image (© OpenStreetMap, © CARTO) must stay visible. We are happy to create another motif or city.

A click downloads the full-size file.