Germany's largest real estate platform, Scout24, has introduced a new conversational assistant powered by advanced artificial intelligence. The tool, named HeyImmo, is designed to guide users through the complex process of finding a home, moving beyond traditional keyword searches to offer a more interactive and personalized experience.
Key Takeaways
- Scout24 has launched HeyImmo, a conversational search assistant powered by OpenAI's GPT-5 technology.
- The new tool functions as a real estate expert, asking clarifying questions and providing tailored summaries and listings.
- Scout24 developed a custom evaluation framework to measure the quality and reliability of the AI's responses.
- An extensive internal testing phase involving nearly all company employees was conducted to refine the user experience before launch.
A Conversational Partner for Home Seekers
Finding a new place to live often involves more than just filtering by price and location. Scout24's development team recognized that users frequently need guidance and support. This insight shifted the project's focus from simply improving search results to creating a comprehensive digital assistant.
"We saw very quickly it’s not only about search," said Gertrud Kolb, Chief Technology Officer at Scout24. "We needed a real-estate expert assistant—a sparring partner—which guides you through the whole platform experience."
HeyImmo is built to understand natural language queries and engage in a dialogue with the user. It can ask follow-up questions to better understand a person's needs, such as their lifestyle, commute preferences, or family requirements. This interaction allows the AI to surface relevant properties that a simple keyword search might miss.
Adapting to User Needs
A significant challenge for the development team was what Kolb refers to as understanding "what intelligent interaction really means." The assistant was engineered to adapt its response format based on the user's request. It can provide concise bullet points, detailed summaries of options, or jump directly to property listings complete with image previews, offering a flexible and user-centric experience.
The Technical Foundation of HeyImmo
The new assistant is powered by GPT-5, one of the latest large language models from OpenAI. While the initial architectural concepts were complex, involving a multi-agent framework, the team opted for a more streamlined approach to accelerate development and gather user feedback quickly.
The final architecture relies on function calling and focused components, a decision that allowed for a faster launch while maintaining performance. The team concentrated on optimizing key metrics such as latency, relevance, and overall performance to ensure a smooth user interaction.
"Be curious, be open, start doing things. Talk with each other, learn from each other—and have fun."
Throughout the development process, Scout24's engineers worked closely with OpenAI's Solutions Architects. Kolb described this collaboration as "immensely helpful" in improving the quality of the AI's answers, structuring responses effectively, and establishing clear benchmarks for what a successful AI-powered search experience should deliver.
A Rigorous Approach to Quality and Trust
Introducing AI into a high-stakes decision like finding a home requires a strong emphasis on trust and reliability. Scout24 addressed this by creating a proprietary evaluation system to define and measure the quality of the assistant's responses.
This custom model, inspired by the OpenAI Evals framework, gave the team a concrete way to determine what "good enough" meant for their customers. It enabled them to systematically test and score the AI's performance across a wide range of scenarios, from simple queries to complex, multi-step requests.
Company-Wide "Swarm Testing"
To prepare HeyImmo for a public release, Scout24 initiated a large-scale internal testing program. Nearly all employees were invited to use the product, provide feedback, and actively try to find its limitations. This "swarm testing" approach was instrumental in identifying edge cases and aligning the final product with real user expectations. The company even postponed the initial launch to ensure the experience met the high-quality bar it had set.
Future Plans and Broader Integration
The launch of HeyImmo is just the first step in Scout24's broader AI strategy. The company is now focused on expanding the assistant's capabilities across its entire ecosystem, which connects property seekers, homeowners, landlords, and real estate agents.
Future applications could include helping agents generate verified floor plans or providing homeowners with personalized market insights. The goal is to deepen the user experience for every group within the marketplace, creating a more interconnected and efficient platform.
"For each customer group we have so many ideas for AI-driven features," Kolb stated. "We’re only just getting started."
This initiative reflects a growing trend in the technology industry, where companies are leveraging generative AI to transform core product experiences. By focusing on quality, user guidance, and iterative development, Scout24 aims to set a new standard for how technology can simplify one of life's most significant decisions.
