FenX raises CHF 8.2 million to advance sustainable mineral foam insulation

02.10.2025 09:09, Rita Longobardi

Swiss cleantech FenX is scaling up its mineral foam technology for building insulation after raising CHF 8.2 million in Series A funding. The capital will help the company industrialize production, grow partnerships, and develop new applications for its panels.

The ETH spin-off FenX is developing a mineral foam designed to replace conventional mineral wools and EPS panels in construction. FenX’s panels, often described as “stones made of ~98% air,” combine low weight with high performance. They are non-combustible, cost-competitive, and made using circular inputs through a low-energy process suitable for both façades and interior applications.

FenX operates an asset-light model, supplying foaming additives and technology licenses to construction insulation manufacturers. The first customer, Çimsa, is commissioning an industrial production line in Spain, aiming for initial output by the end of 2025.

The new funding will allow FenX to industrialize its mineral foam technology, expand strategic partnerships, and launch additional product lines. Beyond insulation panels, the startup is exploring broader applications, from semi-structural materials to carbon sequestration, using its mineral foam platform to deliver high performance with minimal resources. With its first factory underway in Spain, FenX is positioning itself for international growth through collaborations with leading construction materials companies.

The Cleantech startup has been ranked among the Top100 Swiss Startups, has won Venture Kick, and participated in Venture Leaders Cleantech.


FenX team