Monarto Safari Park Visitor Centre

An Elemental Architecture

Representing the meeting of two worlds, the intersecting circles of this symbolically rich building posed numerous technical challenges which were ultimately resolved through the strength and versatility of BlueScope steel walling and roofing.

Spanning 1500 hectares and home to more than 500 animals, Monarto Safari Park is one of the largest open-range zoos in the world. As it emerged from the ground, this new Visitor Centre was probably only visible to the 11 giraffes that call the Park home, but it’s difficult to imagine them being at all fazed by the experience, as the building seems like it’s always been there.

The Centre’s earthy hues – created by a virtuoso combination of interlocking panel walling made from REDCOR^® weathering steel and rammed earth – unite with the curved forms of the design to produce a building that is as primordial as the animals within it and as elemental as the landscape it inhabits. While the landscape in this case might be the Mallee plains of Australia, with a careful rearrangement of similar elements you could just as easily be in the Matabo Hills of Africa.

Referencing the juxtapositions and connections between these two different worlds was one of the key launch points for the design concept. This idea is addressed in form – two ribbon-like curves meet and overlap to create a central gathering space – but also aesthetically, with each arc presenting in a different material.

A further central pillar of the brief was to reflect the Park’s conservation message through the inclusion of sustainable design features and natural materials. While early concepts explored using different materials for each C-shape form, the architects, construction company and cladding contractor workshopped alternative options and came to a preferred option in the form of steel.

“We had a good hard look at ourselves and just asked, ‘What are we trying to achieve?’ We kept coming back to the desire to have a building that would weather over time – something in this landscape shouldn’t require treatment or maintenance,” explains Terry Boxall, architect and director at Intro Architecture. “I’d always wanted to use the weathering steel product, so we found the right pan profile and presented to our client, Zoos SA, the fact that it was a product manufactured in Australia and that we wouldn’t have to re-treat it. It ticked all the right boxes and in the end the client loved it too – I couldn’t imagine it being anything else now.”

For project manager, David Harris of Mossop Construction + Interiors, the walling made from REDCOR^® weathering steel delivered further benefits as a product for the client. “It was quite a significant cost saving. We were obviously trying to achieve the budget that the client had, and REDCOR^® weathering steel was one of the ways of doing it while still maintaining the look and feel that the architect was looking for,” says Harris.

When it came to covering the building’s majestically curved form from above, the architects quickly settled on roofing made from COLORBOND^® steel in the Shale Grey™, and the profile Fielders FreeForm^® to technically accomplish its shape.

The Fielders FreeForm^® profile’s tapered application minimised the need for flashings – also made from COLORBOND^® steel in the colour Shale Grey™ – offering watertightness with minimal material waste. “When we were first thinking about solutions for the roof, we went straight to Fielders FreeForm^®,” says Boxall. “We didn’t go anywhere else because the Fielders FreeForm^® roofing product is one of the few roofing types that could achieve what we were looking for. Its pans are tapered and obviously the smallest taper in the pan is the tighter arc – and then when there’s a larger arc, it’s tapered out. There were two or three different roof radii and we spent a fair bit of time working on how those pans were going to come together.”

The use of rammed earth also provides passive cooling and insulating properties with little or no ongoing maintenance. Steel had a supporting role to play – literally – for this ancient construction technique, where a soil mix is compacted in formwork to roughly half its original volume. One of the more challenging zones of the build was where generous entryways cut through the rammed earth walls, framed by large steel lintels.

“The cave-like entry portal is a complex piece of geometry – the steel headers are curved in plan and in elevation,” says Boxall. “Everything was modelled in three dimensions architecturally and by the structural steel fabricator. These steel lintels forming the portal opening are also structural, requiring a lot of back-and-forth with the rammed earth contractor and the steel fabricators to achieve the desired aesthetic.”

Joining this back-and-forth was Ben Rice, structural engineer at MLEI. He explains that “the curved design resulted in a lot of lintels, in particular, that sit on the walls for the openings. Any beam that’s on a curve is complex as it goes into bending and into twisting at the same time, so there’s a lot more demand on all the steelwork as a result of the curve, and additional challenges for us to be able to resist some of those loads.”

Rice had worked with rammed earth previously on residential projects but Monarto was on a larger scale and following an engineering assessment, steel columns were embedded into the rammed earth in some locations for additional strength.

Rammed earth and steel need to be carefully managed as bedfellows, but the combination certainly provides an impressive arrival moment. Boxall said this was an essential device to signify the bridge between the various worlds that the Park brings together: animal, human and landscape.

“Entering through the main portal of the building is like discovering a different land, which is one of the original concepts of the project: that you’ve left Australia and entered Africa – you’ve physically passed through the portal, which is signified with the cave-like structure.”

STEEL DETAILS - A TECHNICAL DIVE INTO MONARTO SAFARI PARK VISITOR CENTRE

With African and Indigenous references informing the design concept, it was important for the façade of Monarto Safari Park’s new Visitor Centre to have the appearance of being natural in its setting. The deep ochre hues and patina of the walling made from REDCOR^® weathering steel definitely help the Centre to meld with the surrounding landscape. Happily, the material had additional advantages for the project.

Material durability and longevity were a key issue for the client. REDCOR^® weathering steel was suited to local conditions of an inland South Australian environment, developing a protective patina that tightly adheres to the base steel and consequently achieves a lower corrosion rate over extended timeframes compared with other conventional structural steels. The versatility of the product, in being able to be formed into 200-millimetre-wide interlocking panels, also allowed the cladding to deliver the tight curves of the building’s design.

At this pan width, what is actually a faceted wall appears curved, which was critical to the architect’s vision. SA Construct’s Jarrad Morgan says it was a straightforward process to form the panels made from REDCOR^® weathering steel coil.

“We bought the 0.7BMT weathering steel coils and slit them to size, then we ran them through a Schlebach Quadro machine [a sheet metal profile shaping system], and that formed them into interlocking panels,” says Morgan.

“Those are cut to length, stop-ended and then installed on the top-hats in a left-to-right fashion. The top-hats were rolled to follow the radius of the wall curve and keeping the panel width at only 200 millimetres meant that the individual panel pieces worked their way around the curve quite well. It was very successful.”

It all meant that, once again, the SA Construct team gave the Pittsburgh lock seam a good workout. “Anything that’s horizontal and following a curve is difficult,” says Morgan.

“Every segment is custom because the curvature of the wall might be changing slightly through manual tolerances. Everything’s perfect on a drawing, but the way of construction might mean the radius in certain areas is just fluctuating, so what the curve is to that area has got to be marked out.”

A template was made on-site and then taken back to the workshop to be cut from steel and then seamed by hand. Morgan acknowledges it is an ‘old school’, manual process, but both he and Harris agree that wall panelling made from REDCOR^® weathering steel was the best solution for the job, with significant overall cost benefits arising from reduced ongoing maintenance.

The ability of the panels to give the appearance of a curve is just one of many attractive aspects of the design. Perhaps it’s only fitting that in a project about different worlds meeting, we have both old and new methods of steel fabrication combining to resolve the increasingly complex aspirations of contemporary architecture.

TO LEARN MORE ABOUT THE PROJECT, PLEASE WATCH THE VIDEO BELOW.