Build Roofing Cost Calculator Funnel with Google Maps / Roof Size API Integration

We are a residential roofing company looking to build a roofing cost calculator / lead generation funnel. The key requirement is that the funnel must have a way to estimate or retrieve the roof size from the homeowner’s address. Ideally, the flow would look something like this: User enters ZIP code or address Address is confirmed using Google Maps / Google Places autocomplete System pulls or estimates roof size using an available API or integration User answers a few qualifying questions: Do you own the home? What type of project do you need? Approximate roof age Timeline Interested in financing/monthly payment options? User enters name, phone, and email Phone number is verified by SMS code/OTP before final submission User receives a rough roof cost range or “next step” message Lead is sent into GoHighLevel with all fields mapped properly Optional: user can schedule an inspection after submitting We need someone who can recommend and implement the best technical solution for roof-size estimation. Possible options may include: Google Maps / Google Places API Google Solar API / Project Sunroof-style data or similar roof measurement APIs/tools Any other reliable method you recommend for getting roof size from an address Please explain in your proposal what method you recommend for estimating roof size and why. Important: Google Maps alone may show the property, but we need an actual way to estimate roof size or roof square footage. If you have experience with this specific issue, please explain your approach clearly. Deliverables: Branded roofing cost calculator funnel Mobile-first design Address autocomplete / property lookup Roof size estimation method or API integration Multi-step form experience SMS phone verification Lead capture and field mapping into GoHighLevel Basic admin/settings area or clear documentation for editing questions, pricing assumptions, and service area Tracking setup for Meta Pixel, Google Ads conversions, and Google Analytics Nice to have: Experience with roofing, home services, solar, real estate, or lead generation funnels Experience building calculator-style landing pages Experience with GoHighLevel Ability to suggest best practices for improving lead quality and preventing fake phone numbers Please include in your response: Examples of similar funnels/calculators you have built Which roof measurement / roof size solution you recommend Whether you have worked with Google Solar API or similar tools