What it is
Heizkostenvergleich24 helps property owners, building managers, and trade specialists figure out their heating costs and compare heating systems side by side: oil, gas, heat pump, pellets, district heating, and more. The original calculation engine was an old PHP script. I rebuilt it as a modern Flutter Web app on top of a Python Firebase Cloud Function so the same numbers can be embedded anywhere.
Why a custom calculator
Off-the-shelf calculators stop at one heating type or one tariff. Trade specialists need to walk a customer through five or six options on one sheet of paper, with regional prices, subsidies, and realistic 20-year forecasts. That is the gap Heizkostenvergleich24 fills.
Features
- Firebase-based user accounts with two roles: Admin and Fachhandwerker (trade specialist)
- Heating-data management for admins
- Side-by-side comparison of heating types and their costs
- Editable table UI with unsaved-changes detection
- Cloud-synced via Firestore
- Responsive design, works on web and mobile
- Built-in heating-cost calculator running as a Firebase Cloud Function (Python)
- Static landing page (Material Design) for marketing and registration
Architecture
- Flutter Web app: main user-facing application (
flutter_app/) - Firebase Cloud Functions (Python): heating-cost calculation logic, ported from a legacy PHP implementation, modular and extensible across all heating types
- Static landing page: explains the tool, links to registration, surfaces information on heating subsidies (
landing/) - Firebase Hosting: landing and app deployment
- Cloud Firestore: storage for users, heating data, predefined trade-specialist datasets
Tech highlights
app | Flutter Web (Dart) |
engine | Python, Firebase Cloud Functions |
data | Firestore, Firebase Auth |
hosting | Firebase Hosting |
... | and more |
My role
Full-stack: architecture, Flutter app, Python calculation backend, Firebase setup, landing page, deployment.