The most effective way to cut a building’s carbon footprint is to stop heating it when nobody is there. It is also the most boring, which is why most of the world’s offices, schools, and town halls still waste energy on empty rooms. Vilisto, a startup from Hamburg, has spent eight years making that boring problem interesting to the people who pay the bills.
Its product is a self-learning radiator thermostat. It uses motion and temperature sensors to learn a room’s occupancy patterns and automatically turns the heat down when the space is empty. The pitch is simple: plug-and-play hardware, no complex building management system required, with savings that pay for the installation in a few years. The company now reports its devices are installed across more than 35,000 buildings, from Volkswagen offices to city schools, claiming an average heating energy reduction of 32% [StartSupport, 2024].
The Wedge Into Public Procurement
Vilisto’s initial market is the German public sector, a customer base known for long sales cycles but also for deep pockets and a regulatory push for energy efficiency. The company’s case studies read like a municipal directory: the City of Kassel saw nearly 20% savings and is expanding the rollout; an elementary school in Algermissen cut its heating bill by 23%, saving over €16,000 annually [Algermissen case study, vilisto.de]. This focus on public clients provided a predictable, referenceable beachhead. The unit economics are straightforward: the hardware and software are sold as a service, with the energy savings funding the monthly fee. For a city manager facing strict carbon reduction targets, it is an operational expense that improves the budget.
The company’s reported traction suggests this wedge is working.
- Revenue momentum. Turnover reportedly tripled from 2022 to 2023, reaching €6 million, with a target for double-digit millions in 2024 [StartSupport, 2024].
- Headcount growth. The team grew by 100% in the same period, reaching 93 employees [StartSupport, 2024].
- Carbon accounting. Vilisto claims its installed base has saved 10,000 tonnes of CO2 since its 2016 founding, a figure that resonates in public tenders [StartSupport, 2024].
The Capital Behind the Climb
This growth was fueled by a €5 million Series A round in mid-2023, led by SET Ventures with participation from E.R. Capital Holding [SET Ventures, 2023]. The round was modest by Silicon Valley standards but sized for capital-efficient hardware deployment in a proven regional market. The backing from SET Ventures, a specialist climate tech investor, signals credibility in the energy efficiency space beyond mere gadgetry.
2022 Turnover | 2 | M EUR
2023 Turnover | 6 | M EUR
The Incumbent in the Wall
For all its traction, Vilisto operates in a field crowded with legacy players and new digital entrants. Its most direct competition is not another startup, but the inertia of the existing building management system (BMS) and the simple programmable thermostat. The value proposition hinges on being simpler than a BMS retrofit and smarter than a schedule-based thermostat a janitor never reprogrammed.
The risk is that Vilisto becomes a feature, not a category. Large BMS manufacturers like Siemens or Schneider Electric could theoretically bake similar occupancy-learning algorithms into their next-generation controllers, bundling it with a suite of other building analytics. Vilisto’s rebuttal is focus and speed: its device installs in minutes on any radiator, requires no IT integration, and delivers immediate, measurable savings. It is a product for the facility manager who cannot wait for a multi-year capital project.
A back-of-the-envelope calculation illustrates the scale of the bet. If Vilisto’s 35,000 buildings [LinkedIn, Christoph Berger] each save an average of 20% on heating, and a typical German school might spend €50,000 annually on heat, the aggregate annual savings across its fleet could approach €350 million. The company’s cut of that value is its market.
Vilisto’s next twelve months will test whether its municipal wedge can be driven into the broader commercial real estate market across Europe. The company to beat is not a flashy AI startup, but the humble, forgotten programmable thermostat, and the billions of euros in wasted energy it represents every winter.
Sources
- [StartSupport, 2024] vilisto: Thermal management start-up has tripled its turnover | https://startupport.de/en/vilisto-thermal-management-start-up-has-tripled-its-turnover/
- [SET Ventures, 2023] SET Ventures invests in German heat-management startup, vilisto | https://setventures.com/set-ventures-invests-in-german-heat-management-startup-vilisto-2/
- [Algermissen case study, vilisto.de] Lühnde elementary school case study | https://www.vilisto.de/en/
- [LinkedIn, Christoph Berger] Christoph Berger post on company metrics | https://de.linkedin.com/in/christoph-berger