The World Council of Churches (WCC) announced it has contracted with the Implenia Ltd. construction company for the development of the council’s 34,000-square-meter site in Geneva, including the building of a new Ecumenical Center.

The development is expected to take place in several phases over the next five to ten years, according to a WCC news release.

The process will begin with a technical evaluation of the existing buildings, followed by an architectural competition. The winner is expected to be chosen by mid-2013. The beginning of construction work for the buildings, comprising 50,000 to 60,000 square meters of floor space, is planned for 2016-2017, the WCC said. No financial details were announced.

The current Ecumenical Center, which was built in 1964, houses such international organizations as the WCC, Lutheran World Federation and World Communion of Reformed Churches.

“We are looking forward to a fruitful partnership with Implenia who will support us over the whole process with its vast experience and know-how in the development of complex large-scale and sustainable urban projects. For the WCC, the project will offer new perspectives both for our role in international Geneva and for the furtherance of our programs and activities,” said the Rev. Olav Fykse Tveit, WCC general secretary.

In accordance with Geneva’s master plan, the WCC and Implenia intend to maintain the natural character of the site by providing buildings of high environmental quality and by securing belted green spaces and promenades, the WCC said.

“As the land owner, it is our obligation to meet a high level of sustainability by using scarce resources wisely and continuing to create value and exercise responsible stewardship for future generations,” Tveit said.

Implenia will manage the contract from sustainable project development to the construction of all buildings. Based in Dietlikon, near Zurich, Implenia is a leading construction and construction services company. It employs more than 6,000 people and posted revenues of more than 2.5 billion Swiss francs ($2.6 billion) in 2011.

In April, the WCC announced that it had stabilized its pension fund through an extraordinary contribution of 24 million francs and had transferred it to the Profund pension fund manager. At the same time, the WCC said it would turn its attention to development of its Geneva site and announced its partnership with Implenia.