The foil is placed in the excavation pit in advance to protect the foundations of factory and office buildings from rising soil moisture. Tesla has thus opted for a sustainable product made from high-quality, environmentally friendly regenerated materials, entirely in keeping with its own product. 

 
Since 1975, Hammerl has been producing environmentally friendly quality foils and nap mats from regenerative raw materials at its Gemmrigheim site in Germany. As a pioneer and trendsetter in this field, Hammerl, as a partner of the specialist trade, supplies almost all major German projects in the construction industry, such as Stuttgart 21. The construction industry is Hammerl's core business, but the company is also increasingly active in the packaging, garden-landscape construction and agriculture sectors.
 
The company has been part of the Aurelius Group since January 2016.