How I Built an AI App That Rivals Big Tech to Solve My Own Home Project Headaches
March 25, 2025
5 min read
Originally published on Medium.
As a software engineer with a passion for home improvement, I never imagined my frustration with building permits would lead me to create an app that now competes with corporate solutions. But that’s exactly what happened with PermitZen, an AI-powered permit research assistant that’s helping homeowners navigate the bureaucratic maze of local building regulations.
The Frustration That Started It All
It began with seemingly simple projects. I wanted to install an above-ground pool, build a fence around my property, and eventually add a backyard sauna. Like any excited homeowner, I sketched plans, researched materials, and calculated costs. Everything seemed straightforward until I hit the bureaucratic wall: building permits.
The process was maddening:
- Hours spent deciphering outdated municipal websites
- Conflicting information from different sources
- Repeated phone calls to unresponsive permit offices
- Multiple visits to city hall during business hours (while juggling my day job)
- Unclear requirements that changed depending on who I spoke to
As a software engineer, I kept thinking, “There has to be a better way.” I’m used to solving complex problems with code, yet here I was, defeated by paperwork and regulations that seemed intentionally designed to confuse homeowners.
From Frustration to Solution
After my third trip to city hall for my fence permit (only to be told I needed additional documentation), I decided enough was enough. If no good solution existed, I would build one.
The idea for PermitZen took shape: an app that could research local building codes, determine permit requirements, and guide homeowners through the application process — all specific to their address and project type.
What started as a weekend project to solve my own problems quickly evolved. I realized I wasn’t the only one struggling with this issue, and the solution had potential beyond my personal use.
Building the Technical Architecture
As I began developing PermitZen, I knew I needed to create a solution that was both powerful and cost-effective. Big tech companies could throw unlimited resources at this problem, but I needed to be smarter with my approach.
Mobile Frontend with Flutter
I chose Flutter for the mobile app development for several reasons:
- Cross-platform efficiency: Building for both iOS and Android from a single codebase
- Rich UI capabilities: Creating an intuitive interface for complex information
- Hot reload: Enabling rapid iteration during development
The app needed to feel professional and accessible to the average homeowner, not like a clunky government website.
Python Backend on Google Cloud Platform
For the backend, I went with Python running on Google Cloud Run:
- Containerized microservices: Ensuring scalability and reliability
- Serverless architecture: Keeping costs low when usage is light
- WebSocket implementation: Providing real-time updates as the system researches permit requirements
AI Engine: The Secret Sauce
The heart of PermitZen is its AI engine, which combines multiple technologies:
- Claude (Anthropic): Handles complex reasoning about building codes and requirements
- GPT (OpenAI): Generates clear, user-friendly summaries and explanations
- Custom web scraping: Extracts information from municipal websites in real-time
- Browser automation: Navigates municipal websites just like a human would
As the AI researches your project, it asks clarifying questions when needed — much like an experienced contractor would — to ensure accurate results for your specific situation.
Firebase for Authentication and Storage
To round out the stack, I integrated Firebase:
- Authentication: Secure user management with social login options
- Firestore: Storing user reports and project information
- Cloud Storage: Managing documents and generated reports
From Personal Tool to Public Solution
I initially built PermitZen to handle my pool, fence, and sauna projects. The app successfully guided me through:
- Determining exact permit requirements for my address
- Identifying which projects needed professional drawings
- Understanding setback requirements specific to my property
- Discovering that my sauna project qualified for a simplified permit process
- Learning about inspection scheduling and requirements
After using it successfully for my own projects, I realized this tool could help countless other homeowners. I refined the UI, expanded the knowledge base, and launched it publicly.
Competing with the Big Players
What started as a personal project now competes with solutions from much larger companies. Here’s how a solo developer managed to build a competitive product:
- Focused scope: Solving one problem extremely well rather than building a generic solution
- Technical efficiency: Using modern cloud architecture to keep operational costs low
- AI optimization: Leveraging AI models strategically, using each for its strengths
- Domain knowledge: Combining technical skills with real homeowner experience
- Agility: Quickly implementing user feedback without corporate bureaucracy
Results and Impact
PermitZen has now helped homeowners navigate building projects across multiple jurisdictions. The app has:
- Reduced permit research time from days to minutes
- Saved homeowners countless hours of frustration
- Made DIY projects more accessible to the average person
- Allowed homeowners to stay compliant with their insurance company
Users particularly appreciate the personalized guidance that accounts for their specific address and local regulations — something generic advice websites simply can’t provide.
What’s Next for PermitZen
Future plans include:
- Open-sourcing components of the system to encourage community contributions
- Achieving higher accuracy by distilling the knowledge of all US state codes into a knowledge graph to enhance RAG capabilities
- A premium version with step-by-step guidance and preparation for applications and inspections
Lessons Learned
- Solve your own problems first: The best products often come from addressing personal pain points
- Smart architecture beats brute force: Strategic use of technology can allow small players to compete with giants
- Domain expertise matters: Understanding both the technical and subject matter perspectives creates better solutions
- Start focused, then expand: Solving one problem exceptionally well provides the foundation for growth
The barriers to entry have never been lower for creating sophisticated, AI-powered applications. Cloud services, modern frameworks, and API-accessible AI models mean that one passionate developer can build something truly impactful.