TV presenter Nick Knowles will face a completed DIY project of a different sort when he opens Europe's largest orang-utan enclosure.

Nick, who hosts DIYSOS, will take time out on Saturday June 30 to officially open Chester Zoo's Realm of the Red Ape - a new home for critically endangered Sumatran and Bornean orang-utans.

The exhibit opens to the public for the first time this Saturday (May 26) and marks the end of two years' work developing the orang-utans old enclosures into a state-of-the-art tropical home for the orang-utans and a number of other Indonesian forest animals including reptiles, birds, mammals. The enclosure includes some 2,000 plants.

Nick recently returned from a trip to Borneo where he came face-to-face with orang-utans to discover more about their plight in the wild. The film is for the BBC's Saving Planet Earth series in which a number of different celebrities lend their support to threatened species.

Nick said: "Having been to Borneo and seen the orang-utan's natural habitat and the rate at which it's disappearing, breeding programmes and the work being done at Chester Zoo become more important everyday."

Nick will be joined at the official June opening by Dr Birute Galdikas, president of the Los Angeles-based Orangutan Foundation International. Dr Galdikas will be presented with a Gold Medal from the North of England Zoological Association, the charitable trust that runs Chester Zoo. The presentation will mark Dr Galdikas' tireless work on primate conservation and field research - both Bornean and Sumatran orang-utans are critically endangered in the wild.

Mark Pilgrim, Chester Zoo's Director of Conservation and Education, said: "At the current rate of decline, wild orang-utans will be extinct in 10 to 20 years time. It is a frightening fact.

"Conservation breeding programmes in zoos are important but we also have a responsibility to orang-utans in the wild and later this year, we will be launching a programme to assist wild orang-utans in Borneo by protecting their habitat.

"Realm of the Red Ape will enable us to continue with our successful breeding programme and raise support and awareness of the threats facing these charismatic species.

"Dr Galdikas has a long and distinguished record of working with orang-utans. Nick's experiences and work in Borneo will also bring home the message about the plight of the orang-utans. We are delighted that they will both be joining us to mark the official opening of Realm of the Red Ape."

Both Nick and Dr Galdikas will be given a tour of Realm of the Red Ape which offers more space for the zoo's orang-utans. Chester Zoo has kept orang-utans since the late 1950s and more than 25 individuals have been born at the zoo in that time.

The new enclosure, which cost £3.5 million to develop, includes a two-storey building which has been built to link on to the existing orang-utan house and includes three large indoor enclosures. Linked to these are two further large outdoor enclosures covered with a mesh roof and housing tree-like structures to act as climbing frames for the six Sumatran and four Bornean orang-utans and a family of four noisy Gibbons.

Visitors will be taken on a canopy walk where they will meet a wide variety of treetop wildlife including birds, small mammals, amphibians, reptiles and insects. These will include a pair of Crocodile Monitor Lizards, the longest lizards in the world.