When the old ape house (built in 1973) no longer met international standards, Wilhelma had to build a new ape house. In Spring of 2010, the project began to not only meet international standards, but to also include housing for gorillas and bonobos in an outdoor area. The new building, 13 times the size of the original structure at , was opened to the public on May 14, 2013. Construction of the New Ape House wound up costing the zoo about 22 million euros, 70% more than the original 9.5 million euros financed towards the project. The unfortunate deaths of two bonobos thanks to malfunctioning components in the ventilation system have called the construction quality of the building into question.