Porsche and Audi have struck a joint partnership to build an electric car platform to cut down on production costs.

In statements by Audi CEO Rupert Stadler and Porsche CEO Oliver Blume, as told to two German publications, Stuttgarter Zeitung and Stuttgarter Nachrichten, both elaborated on the reasons for the move.

“By 2025, we’re facing a low single-digit billion euro sum to develop the architecture,” said Stadler.

“If both would act on their own, costs would be 30 percent higher,” stated Blume.

Both companies plan on introducing new models using the joint platform starting in 2021, with initial production comprising of two sedans and two SUVs by Audi. Porsche would also build its first model at the same facility used to build the Macan SUV, in Leipzig, Germany.

Other production activities include the hiring of 550 developers by Audi and 300 developers by Porsche.

Both Porsche and Audi comprise Volkswagen Group’s luxury arm, as subsidiaries. In April 2017, both automakers also announced the development of its Premium Platform Electric (PPE) platform for electric cars, along with a separate standalone effort by Porsche called SPR for its sportier vehicles, to be shared by Audi.

Other areas of focus in its shared vehicle architecture strategy include work in digitization and autonomous driving, although very few specifics have been revealed to date regarding its focus in these areas.