Hey HN! Ilya and Nikita here. We’re building HomeCat, a tool that turns a video walkthrough of a property into permit-ready building plans - https://myhomecat.com

The basic workflow is:

1. Record a video of the property.

2. HomeCat picks out details and reconstructs your property.

3. We help you plan and design a project, like a new rear deck.

4. Once you're happy, you get a drawing set containing permit-ready plans (site plan, floor plan, elevations) that are ready for permit submission.

You can explore example scans and download some of the plans we have produced here: https://myhomecat.com/try

The idea came from conversations with homeowners, contractors, engineers, and municipal building departments. Homeowners often did not know what their municipality expected, while contractors spent time hand-drawing plans - only to get rejected, delaying the project. We also manually prepared site plans for several homeowners. Seeing how happy they were pushed us to work on this idea.

The technical pipeline has four main parts.

First, we use computer-vision models to identify elements such as walls, windows, doors, and other objects in a property video, and to estimate their dimensions and positions. We only extract parts of the property that are needed for the permit; we won't extract anything that isn't.

We then convert those elements into a structured building model using a custom, Revit-like BIM system. Designs are assembled from components, which lets us apply local municipality codes like the Ontario Building Code or the California Residential Code.

Next, we evaluate the design against rules we've learned from previous permit submissions. Requirements can vary not only by state or province, but also by municipality and drawing type. We use those rules to include extra detail that allows the permit to be approved faster.

Finally, a custom vector-rendering engine projects the BIM model into to-scale site plans, floor plans, and elevations.

For comparison, here is a deck drawing set prepared around Ontario requirements: https://myhomecat.com/16x16-spacious-raised-deck-5798e862

And here is one prepared around California requirements: https://myhomecat.com/10x12-budget-ground-level-deck-01ba4d7...

And here is a property we scanned recently: https://myhomecat.com/2-storey-semi-detached-dwelling-2a0f4b...

We are still early, and the complete design tool is not publicly available yet. Construction documents have real-world consequences, so we are initially limiting the types of projects and jurisdictions.

Our long-term goal is that in the future, we can empower anyone to plan, design, and get permit-ready plans, in any part of the US and Canada, and for any home project.

We would especially appreciate if you would reach out to us to help you bring your home project to life. We're exploring not just outdoor, but also indoor renovations, and projects that might not even need a permit. And just for the HN community - we can provide initial concept designs for free.