OpenImmo Explained: What the Real-Estate Standard Is and How Import Works

If you market property, sooner or later you'll come across the word OpenImmo – in your agency software, during a portal export or in a conversation with IT. This article explains in plain language what OpenImmo is, how an OpenImmo file is structured, which software exports the standard and how importing into a property portal works. No jargon, but concrete enough to understand what happens behind the scenes.

What is OpenImmo?#

OpenImmo is an open, XML-based standard for exchanging property listings. Instead of re-entering every property in every portal by hand, your agency software exports the data once as an OpenImmo file – portals read it in automatically. The standard is maintained by an industry body and has been established in the German-speaking real-estate market for many years.

The core idea is "maintain once, distribute everywhere": you maintain a property in your system, and via OpenImmo it travels into the portals of your choice without double entry. That saves time and prevents outdated or contradictory listings across platforms.

Why OpenImmo exists at all#

Before the standard, every portal connection was a custom job: each software interface spoke its own format, every integration had to be built separately. OpenImmo solves this by defining one common format. Software that can export OpenImmo is, in principle, connectable to any portal that imports OpenImmo – regardless of vendor.

How an OpenImmo file is structured#

An OpenImmo delivery is usually a ZIP container with an openimmo.xml file and the matching images. The XML describes each property in an <immobilie> element – structured into clearly named areas:

• <objektkategorie> – marketing type (rent/sale) and property type (apartment, house …)
• <geo> – address and geo coordinates
• <preise> – base rent, service charges, purchase price, deposit …
• <flaechen> – living area, rooms, bed-/bathrooms
• <ausstattung> – features such as elevator, balcony, fitted kitchen
• <zustand_angaben> – year built, condition, energy certificate
• <freitexte> – title, description, location description
• <anhaenge> – images, floor plans, documents
• <verwaltung_techn> – technical administration, incl. the unique property reference

Here's what a single rental property (trimmed) looks like:

<immobilie>
  <objektkategorie>
    <vermarktungsart KAUF="0" MIETE_PACHT="1" />
    <objektart><wohnung wohnungtyp="ETAGE" /></objektart>
  </objektkategorie>
  <geo>
    <plz>10115</plz>
    <ort>Berlin</ort>
    <strasse>Invalidenstraße</strasse>
    <hausnummer>12</hausnummer>
  </geo>
  <preise>
    <kaltmiete>1.250,00</kaltmiete>
    <nebenkosten>250,00</nebenkosten>
  </preise>
  <flaechen>
    <wohnflaeche>72,5</wohnflaeche>
    <anzahl_zimmer>2,5</anzahl_zimmer>
  </flaechen>
  <freitexte>
    <objekttitel>Bright 2.5-room apartment in Berlin-Mitte</objekttitel>
  </freitexte>
  <verwaltung_techn>
    <openimmo_obid>OBID-ABC-123</openimmo_obid>
  </verwaltung_techn>
</immobilie>

The "action": create, update or delete#

Every property carries an action that tells the portal what to do:

• CHANGE (or no value): create the property or – if it already exists – update it.
• DELETE: remove the property. Good portals then archive it instead of hard-deleting it, so applications and appointments are preserved.
• REFERENCE: just a reference, skipped on import.

Which software exports OpenImmo#

The standard is supported industry-wide. Common tools that export OpenImmo include ImmoScout24, onOffice and FlowFact – but the list is not exhaustive. What matters is not the vendor but whether your software handles the export in the OpenImmo 1.2.x standard. If it does, your portfolio is, in principle, connectable to any OpenImmo-capable portal.

How importing into a portal works#

Using WOHNO as an example, the path from export to finished listing looks like this:

1. 1

   Export in your software

   You create an OpenImmo export in your agency software – usually a ZIP with the openimmo.xml and the images.

2. 2

   Upload the file

   You upload the ZIP – or a single openimmo.xml – to the portal. WOHNO processes up to 200 properties per file.

3. 3

   Automatic mapping

   The portal reads the standard elements and maps them to the matching listing fields: property type, prices, areas, features, energy certificate, address, geo coordinates and images.

4. 4

   Review & publish

   You review the imported properties and take them live – within your plan limit.

Exactly which OpenImmo elements map to which fields is shown in the field-mapping table on the OpenImmo import page.

Conclusion#

OpenImmo is the backbone of data exchange in the real-estate industry: an open XML standard that makes double entry unnecessary. If your software exports OpenImmo 1.2.x, your portfolio is in a portal like WOHNO within minutes – including images, energy certificate and geo data, with reliable matching on re-import.

FAQ – frequently asked questions#