OPENLY 50° Climate Resilience - Construction Diary, Phase 2

-10° in winter, +40° in summer
The Openly Valley Widnau Stage 2 is dedicated to climate resilience.

Further developments:

• Solar Slider: PV sliding shutters for shading and electricity generation, a new development in collaboration with Schenker AG

• Nighttime Cooling: Airbox 2.0
  More affordable, quieter, and—above all—plug-and-play. No more need for on-site installation or electrical design planning.

• Hemp-lime: U-value of 0.15 (Minergie P Standard):
  Mass production of exterior walls on Cancret Materials’ new production line

• Lehm Cancret LBD 1 ceiling system with clay on the underside. Cost-neutral compared to the box-girder ceiling used in Phase 1

• Clay interior walls , a new drywall system featuring a 12.5-mm clay building board (available from Cancret Materials).

• Solar-powered cooling system in floors and clay ceilings

• Eco-Concrete vs. Biochar: Concrete with the Same Net CO2 Footprint

Through consistent refinement and industrialization of our construction system, we are now able to achieve construction costs of approximately 925 CHF/m3.

Invitation to Construction Site Open House During the Topping-Out Ceremony for the Wooden Structure

Fri, Oct. 9, 2026, 10 a.m.–12 p.m.

Wed, Oct. 14, 2026, 10 a.m.–12 p.m.

Tue, Oct. 20, 2026, 3:00–5:00 p.m.

Thu, Oct. 29, 2026, 4:00–6:00 p.m.

More info & registration here

Basement: Concrete, Yes—But With a Clear Conscience

Pouring the floor slab: The mix, which included CO₂-reduced cement from Holcim Eco Planet, was supplied by network partner Sigmund Sieber AG specially adapted for this application and placed by Gautschi AG .

A “white tub” is almost impossible to make without concrete. From Openly’s perspective, however, traditional concrete—as an emission-intensive material—is precisely the product we want to reduce as much as possible. The solution: low-carbon cement (Holcim Eco Planet). However, this cement behaves very differently from conventional concrete during processing—the mixture is more viscous and requires a different consistency during preparation.

Learn more about concrete here.