Dudley Zoo revamp will make waves for years

And now the iconic wave entrance at the attraction in Castle Hill is being carefully restored to ensure it welcomes many more families for years to come.

The eye-catching building is one of two of the zoo's historic Tecton structures, which were first constructed more than 70 years ago, using pre-stressed concrete – a pioneering system at the time.

And now staff are carrying on the tradition with ground-breaking work to carry out repairs on two of these famous structures – the first time this has been done with concrete buildings.

The Tecton structures date back to the mid-1930s when architects were able to mould the concrete to create attractive enclosures to fit in with the landscape and the steep slopes of the Castle Hill site.

Today the zoo has the world's largest single collection of Tecton buildings and in 2009 all 12 structures received World Monuments Fund status, alongside Machu Picchu and the Taj Mahal.

The wave entrance and the Safari Shop are among four that are being renovated thanks to cash from part of a wider £1.15 million lottery-funded programme.

Work began in September and has seen the zoo join forces with history experts to ensure accurate materials and techniques are used.

Members of the 20th Century Society have helped the attraction find the exact concrete formula used to make the buildings so it can be recreated for the restoration. Meanwhile zoo chief executive Peter Suddock has also attended a four-day course in Sussex on concrete mixing and building repair to understand the work involved.

He said: "It's going really well. We started at the end of September with the aim of getting the concrete repairs done before Christmas and we're looking on target.

"We needed to get them done before it gets frosty as it's too cold then to work on the concrete."

During the work staff have also discovered the original paint scheme for both the shop and entrance – terracotta red and a light sky blue, which they are looking to recreate. "It's looking really brilliant. We're discovering things we didn't know about," Mr Suddock said.

"We found the original slab floor in the shop and we've been looking at how to make it fit for modern use."

Following Christmas the windows, glass and doors will be installed in the shop before it is fitted out ready to welcome visitor by Easter.

During the work, which has seen the zoo run an apprentice-training scheme with Dudley College, the shop's contents and sign have been relocated to a temporary site next to the chairlift. The turnstiles will be re-fitted in the wave entrance with the concrete given a lick of paint.

In March work will start on the other two Tecton structures due to be refurbished - the bear ravine and kiosk 1.

The restoration project, which also included repairing and re-opening the chairlift last year, is being boosted by the zoo, which will invest £600,000 on a retail complex, Tecton interpretation centre and upgrading toilets and food outlets. New service roads are also being constructed.