We started Keystone because we kept hearing the same story.

We have been friends for more than five years. Henry studied mechanical engineering and has spent his career working with both software and hardware — most recently building and flying drones for inspection. Paulo studied computer science and works in cybersecurity, keeping complex systems safe and organised.

Both of us grew up around old homes and estates. Beautiful, demanding buildings — the kind with roofs you cannot see from the ground, chimneys you cannot reach without scaffolding, and valleys that only show their true condition after something has already gone wrong.

The idea for Keystone came while we were traveling together, visiting castles and estates across Europe. We kept meeting owners who did not have a clear view of their building's condition. They would discover leaks, cracks and rot years too late — always from the inside, always after water had already found a way in.

We started helping out the simplest way we knew: by flying a drone, capturing the roofs and facades in high resolution, and turning what we saw into a clear report. The response was immediate. People finally had a picture of what was happening on their own building.

That is now Keystone. Once or twice a year, we fly your building, capture every roof plane, chimney, gutter and facade, and turn those images into a measurable 3D model. Each element is scored, the reasoning is recorded, and anything that needs attention is flagged. You get a private dashboard, a dated photo archive, and a record that improves year after year.

When you work with Keystone, you work with the two of us — based in Europe, usually able to be on site within a week, and accountable for every image and every score.

Our goal is not to find problems. It is to give you complete peace of mind.

If you own a building with fabric worth protecting, we would love to show you what a proper report looks like.