# Top 18 Building Energy Efficiency Startups Worldwide by Funding (2026)

> The 18 best-funded building energy efficiency startups worldwide, ranked by total funding raised: $67M combined.

Source: https://millionrounds.com/top-lists/building-energy-efficiency-startups (Millionrounds; every figure on the page links to its filing or article)

- 1 [**Charge Robotics** Charge Robotics is dedicated to advancing the renewable energy sector by automating the labor-intensive stages of solar construction.](https://millionrounds.com/company/charge-robotics) Charge Robotics is dedicated to advancing the renewable energy sector by automating the labor-intensive stages of solar construction. *Founded* 2021 San Leandro, United States **$17M** last round Aug 2024
- 2 [**re.green** re-green is a Frankfurt-based company founded in 2023 that specializes in enhancing the energy efficiency and ESG compliance of commercial real estate.](https://millionrounds.com/company/re-green) re-green is a Frankfurt-based company founded in 2023 that specializes in enhancing the energy efficiency and ESG compliance of commercial real estate. *Founded* 2023 Atlanta, Brazil **$14M** last round May 2025
- 3 [**Terion** Terion is an AI-based energy management software company based in Copenhagen, Denmark.](https://millionrounds.com/company/terion) Terion is an AI-based energy management software company based in Copenhagen, Denmark. *Founded* 2024 Copenhagen, United States **$11M** last round Sept 2002
- 4 [**Measurable.energy** measurable.energy is a UK-based clean-tech and PropTech company that focuses on AI-driven plug load management and energy efficiency solutions for commercial bu](https://millionrounds.com/company/measurable-energy) measurable.energy is a UK-based clean-tech and PropTech company that focuses on AI-driven plug load management and energy efficiency solutions for commercial bu *Founded* 2018 Reading, United Kingdom **$5.2M** last round Aug 2025
- 5 [**WegoWise** WegoWise is a web-based utility analytics platform that integrates big data with energy efficiency for the building performance industry.](https://millionrounds.com/company/wegowise) WegoWise is a web-based utility analytics platform that integrates big data with energy efficiency for the building performance industry. *Founded* 2010 United States **$4.9M** last round May 2013
- 6 [**viboo** viboo is a Swiss proptech startup founded in 2022, based in Dübendorf, Switzerland.](https://millionrounds.com/company/viboo) viboo is a Swiss proptech startup founded in 2022, based in Dübendorf, Switzerland. *Founded* 2022 Duebendorf, Switzerland **$4.7M** last round Sept 2025
- 7 [**Octopus Lab** Octopus Lab is a French deep tech company focused on predictive software solutions that improve indoor air quality (IAQ), energy efficiency, and environmental s](https://millionrounds.com/company/octopus-lab) Octopus Lab is a French deep tech company focused on predictive software solutions that improve indoor air quality (IAQ), energy efficiency, and environmental s *Founded* 2017 La Madeleine, France **$3.1M** last round Jul 2022
- 8 [**Baryon** Baryon develops energy efficiency technologies with applications in building cooling, water production, cold chain, and others.](https://millionrounds.com/company/baryon) Baryon develops energy efficiency technologies with applications in building cooling, water production, cold chain, and others. *Founded* - Wilmington, United States **$2.1M** last round Aug 2021
- 9 [**Energie Solutions Air** Énergie Solutions Air (ESA) provides heat exchangers and energy efficiency for hog and fowl farming buildings.](https://millionrounds.com/company/energie-solutions-air) Énergie Solutions Air (ESA) provides heat exchangers and energy efficiency for hog and fowl farming buildings. *Founded* 2010 Canada **$1.0M** last round Jan 2018
- 10 [**Helicomm** Helicomm provides wireless communication for monitoring and control products to facilitate clean technology deployment worldwide.](https://millionrounds.com/company/helicomm) Helicomm provides wireless communication for monitoring and control products to facilitate clean technology deployment worldwide. *Founded* 2002 Shindian, United States **$1.0M** last round Mar 2006
- 11 [**Carnot Innovations** Carnot Innovations is a technology company based in Hong Kong, focusing on AI-driven energy efficiency and sustainability solutions for the building management sector.](https://millionrounds.com/company/carnot-innovations) Carnot Innovations is a technology company based in Hong Kong, focusing on AI-driven energy efficiency and sustainability solutions for the building management sector. *Founded* 2018 Hong Kong SAR China **$800K** last round Nov 2019
- 12 [**VASS Technologies** VASS Technologies is an Italian construction and building-tech company specializing in high-efficiency roofing solutions.](https://millionrounds.com/company/vass-technologies) VASS Technologies is an Italian construction and building-tech company specializing in high-efficiency roofing solutions. *Founded* 2012 Carmagnola, Italy **$780K** last round Oct 2012
- 13 [**Wattblock** Wattblock is an Australian energy-efficiency and consulting company founded in 2014, based in Mosman, New South Wales.](https://millionrounds.com/company/wattblock) Wattblock is an Australian energy-efficiency and consulting company founded in 2014, based in Mosman, New South Wales. *Founded* 2014 Sydney, Australia **$551K** last round May 2015
- 14 [**Cypress Envirosystems** Cypress Envirosystems, based in San Jose, California, specializes in non-invasive retrofit and digital overlay solutions for existing buildings and industrial facilities.](https://millionrounds.com/company/cypress-envirosystems) Cypress Envirosystems, based in San Jose, California, specializes in non-invasive retrofit and digital overlay solutions for existing buildings and industrial facilities. *Founded* 2007 San Jose, United States **$466K** last round May 2013
- 15 [**QwikSense** QwikSense is a Netherlands-based company that specializes in workplace environment analytics and smart building monitoring.](https://millionrounds.com/company/qwiksense) QwikSense is a Netherlands-based company that specializes in workplace environment analytics and smart building monitoring. *Founded* 2014 Bussum, Netherlands **$291K** last round May 2015
- 16 [**Whisper Energy** IoT; Sensors, Smart Building, Energy Efficiency](https://millionrounds.com/company/whisper-energy) IoT; Sensors, Smart Building, Energy Efficiency *Founded* - Marina Del Rey, United States **$155K** last round Jul 2025
- 17 [**Kestrix** Kestrix is a climate technology and energy efficiency startup founded in 2022 by Lucy Lyons and Matt Goodridge.](https://millionrounds.com/company/kestrix) Kestrix is a climate technology and energy efficiency startup founded in 2022 by Lucy Lyons and Matt Goodridge. *Founded* 1991 London, United Kingdom **$136K** last round Jun 2025
- 18 [**HomeWellness** HomeWellness, a virtual building science expert, facilitates decision making in improving homes' comfort, health and energy efficiency.](https://millionrounds.com/company/homewellness) HomeWellness, a virtual building science expert, facilitates decision making in improving homes' comfort, health and energy efficiency. *Founded* 2013 Durham, United States **$50K** last round Sept 2013

**Total funding** how the list is ranked

**15 November 2026** updated nightly

**Rounds we track** source: Millionrounds

Companies whose own description names this theme, ranked by the total they have raised in rounds we hold. Nobody pays to be on a list.

## Who backed them?

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## More lists worldwide

[See all](https://millionrounds.com/top-lists?r=Global)

[*GV* *V* *RP* **Health startups worldwide** 12,811 companies · $81B](https://millionrounds.com/top-lists/health-startups)[*O* *A* *X* **AI startups worldwide** 10,238 companies · $830B](https://millionrounds.com/top-lists/ai-startups)[*GV* *V* *RP* **Biotech startups worldwide** 7,127 companies · $70B](https://millionrounds.com/top-lists/biotech-startups)[*D* *B* *FT* **Big data startups worldwide** 3,812 companies · $220B](https://millionrounds.com/top-lists/big-data-startups)[*AF* *R* *S* **Fintech startups worldwide** 3,200 companies · $94B](https://millionrounds.com/top-lists/fintech-startups)[*O* *A* *B* **AI startups that raised in 2026** 2,922 companies · $540B in 2026](https://millionrounds.com/top-lists/ai-startups-raised-2026)[*FT* *CE* *P* **Energy providers startups worldwide** 2,808 companies · $152B](https://millionrounds.com/top-lists/energy-providers-startups)[*A* *P* *O* **Marketing tech startups worldwide** 2,728 companies · $28B](https://millionrounds.com/top-lists/marketing-tech-startups)