We make residential projects simple, fast and predictable.

In everyday project work

Renaldo is a software and training company based in Hamburg, Germany.

Experience, turned into a tool.

We first met back in 2019 at ecoworks. In October 2023 a LinkedIn post by Ronald about his “retrofit sprint” in Hamburg-Duvenstedt was the trigger: Gregor picked up the phone, the planned quick call turned into an hour — and just before Christmas, on 21 December 2023, we founded Renaldo together.

The goal back then: make retrofitting single-family homes in Germany simpler, faster, safer and cheaper — first with the retrofit sprint, then with the Renaldo app. Today the same ambition covers all of residential construction: new build and retrofit, from single-family houses to apartment buildings. Because the questions are the same everywhere — what does this reliably cost, who does what, and when. That way we want to help thousands of homeowners, planners and retrofit coaches deliver projects that hold up to their promises, and to contribute against climate change by speeding up energy efficiency and the switch to low-carbon heating.

Rethinking residential buildings.

Building and retrofitting in Germany has to become faster, fairer and more transparent — and that only works when homeowners, professionals and lenders speak the same language.

Renaldo is what holds it together. One data room, one AI, three worlds. Not a tool built to impress — one built to save hours.

Our guiding principle: think about a building project from the end backwards.

Cost certainty first, then the plan — because every contractor invoice ultimately comes down to work item × quantity × unit price. New build or retrofit, single-family house or apartment building: those are exactly the three figures Renaldo makes reliable from the very start.

Renaldo founded

A few weeks after Ronald's sprint in Hamburg-Duvenstedt, the decision was made on 21 December.

As a general contractor

Three retrofit sprints run in-house — twice in Hamburg, once in Markkleeberg near Leipzig.

As a digital design practice

Numerous retrofit projects and sprints supported through design and delivery.

Tools that save hours.

Not features that impress — features people actually touch.

Transparent pricing.

No small print, no lock-in contracts, cancel monthly.

Taking GDPR seriously.

Servers and database in Germany, files in the EU, no selling of data, analytics only with your consent.

Built with real clients.

Every feature is tested with people doing the work before it goes live.

Hamburg is home.

A Hanseatic city with a long view: trades, design and entrepreneurial drive all meet here — and projects like yours grow in between. We work out of Hamburg-Sasel, quiet and green in the north of the city, a short hop from sites and partners across the metropolitan region. Weather, water and plenty of room to think — which suits building rather well: matter-of-fact, down to earth, quality over frills.

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