Formerly spread across 12 different buildings on Porsche's development center in Weissach, Germany, engineers doing electrical and electronics work now are co-located as part of an expansion at the Weissach campus. Porsche on July 18 officially announced the opening of the electronics integration center and two other new buildings in the automaker's largest-ever investment (more than $200 million) in the Weissach campus. The other new buildings are a wind tunnel (the most expensive of the three buildings) and a design studio with concept car construction facility. The studio and wind tunnel facilities were sited right next to each other for faster aerodynamics testing of design concepts. More than 6000 employees from Porsche (4500) and partner companies (1500) are currently working at the Weissach campus in R&D, motorsports, purchasing, and supporting fields. Porsche claims its new facility gives it unique development capability, from concept to production testing. It also stated that in 2013 the company invested "well over $2 billion" in R&D (roughly 11% of total revenues).