Union Berlin have announced plans to increase the capacity of their Alten Forsterei stadium from 22,012 to around 37,000 by 2020.
The €38 million reconstruction work, due to begin in 2019, will mean the stadium has a standing capacity of 28,692 -- just short of the 29,400 at Borussia Dortmund's Westfalenstadion.
Seating capacity, meanwhile, will be increased to more than 8,000 seats to meet German Football League requirements for top-flight football.
Union want the Alten Forsterei, built in 1920 and set in the woods of Kopenick, a Berlin suburb, to "keep its character and remain unique."
Wollt Ihr Euch den Film zur Stadionerweiterung nochmals anschauen? Schön das Ihr heute hier wart #fcunion #stadaf https://t.co/Fy1H6Q29OI pic.twitter.com/6KHErtFkqR
- 1. FC Union Berlin (@fcunion) June 20, 2017
In a statement on the club's official website, president Dirk Zingler said: "It was important to us that this historic place for our club grows to meet future requirements. We want a tight stadium with standing terraces."
The second-tier club narrowly missed out on promotion to the Bundesliga for the first time ever last season, finishing in fourth place.