Mortgage Moment

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Check your personal road to home ownership within 30 seconds, at Mortgage Moment 🏡

Inspiration

In Munich, even high earners have given up on buying a home because they assume it is impossible. However, market data shows a different reality where rents are exploding while purchase prices in commuter towns like Garching are cooling. We realized there is a specific mathematical point where buying becomes cheaper than renting. We call this the Mortgage Moment. We built this tool to show tenants this data and break their resignation.

What it does

Mortgage Moment is a physical-to-digital intervention. The Trigger: It starts with a physical demo poster (displayed on our whiteboard) featuring a QR code and the hook "72 neighbors bought here recently." The Reality Check: Users scan the code and enter just three numbers: Net Income, Rent, and Equity. No login required. The Calculation: Using the Interhyp Budget Calculation API, we determine exactly how much property the user can afford based on their income and equity. We compare this potential mortgage payment against their current rent to show the financial impact. The Solution: We display map-based listings fetched via the ThinkInno API that fit the user's calculated budget. If they cannot afford homes in their area, they see an Affordability Coach, which displays how much money is missing, what the estimated required additional monthly income is and how much they can save up for their children (so they can afford a down payment in the future!). Additionally, the coach displays more affordable neighbourhoods. Momo & Summary: An AI voice assistant (Momo) answers questions about listings. Users can receive a detailed email summary of a property either by clicking the mail button or simply by asking Momo to "send me the info" during the call.

How we built it

The frontend is built with React and Vite (JavaScript). The backend is an Express server deployed on Railway. The domain is managed via Cloudflare. We use the OpenAI Realtime API (WebRTC) to power "Momo" for low-latency, natural voice conversations. For the financial logic, we integrated the Interhyp Budget Calculation API to determine strict affordability limits. Real estate listings are sourced dynamically using the ThinkInno API and displayed on a map using the Google Maps API. We combined this with custom-scraped market data to determine local price trends. Brevo handles the transactional emails.

Challenges we ran into

The main challenge was psychological, not technical. How do you prompt a user to check mortgage affordability when they have already decided it is impossible? We iterated heavily on the "Hook" (the poster copy) to overcome this apathy. Technically, balancing the "Safe Affordability" calculation was tough. We had to abstract complex banking math into a simple UI without being financially irresponsible or giving false hope.

Accomplishments that we're proud of

We built a functioning prototype with functional real-time voice and email integrations, which is live. On top of that, we believe that through a proactive approach (physical posters) to address people who have previously “opted out” of home-buying due to economic circumstances, we can take a first step in shaping their individual home-buying journey.

What we learned

We learned that "affordability" is a data visibility problem. We found that while Munich is tough (but still manageable!), the "Mortgage Moment" is wide open in Eastern Germany (Chemnitz) or specific suburbs. Also, people don’t start to look into how to buy and finance a home, because they believe it is simply impossible due to the general or their specific economic situation. People must check the handle before assuming the door is shut!

What's next for Mortgage Moment

We want to automate the "Moment Detection" backend to monitor every municipality in Germany and trigger alerts automatically when the Buy-vs-Rent math flips. We also plan to establish the Interhyp integration so users can pass their "Momo" data directly into a financing application.