Its reinforced rammed earth walls, wrapping spotted gum façade and “horse pond” will be the talk of the architecture community for some time, but the roof at this Equestrian Centre project in Merricks, Victoria should not be [under]over looked.
Located on Victoria’s Mornington Peninsula, the Equestrian Centre is the combined design effort of London studio Seth Stein Architects and local firm Watson Architecture + Design.
The 1,000sqm complex is set on an undulating site that was levelled and drained before construction and was designed exclusively for the breeding of warm blood eventing horses.
The stables are framed by a reinforced wall of rammed earth that runs along the southern border of the levelled section of the site in a reverse-J shape, offering robust protection from southern weather elements.
The majority of the building is made from laminated plantation Tasmanian Oak (structural) and Class One, Spotted Gum (cladding) and has a constant and relatively narrow cross section to aid cross ventilation and natural convection. The facility faces north and is shaped like a crescent to allow for easy access from all of the stables to the adjacent lawn which functions as a paddock for jumping and event practice.
On top of it all is a slender mono-pitched skillion roof that wraps with the rammed earth wall in that defining reverse-J shape along the site. The structural and civil engineers for the project, Perrett Simpson Stantin (PSS) said there were a number of considerations that affected the roof profiling and detailing.
The groove in the top of the rammed earth wall integrates a stream that flows out to meet a small pool of water where horses can cool off. The wall comprises a low-moisture mix of natural soil and cement compacted around reinforcing bars. 
The beams are tapered at their cantilevered ends and topped with plywood lining boards.
Because of its location the site receives a heavy battering from prevailing south westerly winds and therefore lateral wind loads and uplift were both important influences on the 1,260sqm roof’s design and material composition. The LVL chosen by PSS and the architects for the roof joists was a GL17 rated plantation Tasmanian Oak product, sized at 233x60mm and spaced at 900mm centres. All the timber components of the building were shop drawn and fabricated to tight tolerances.
According to the architects the reinforced rammed earth wall is more cost-effective than off-form concrete and, once a 600-millimetre tier of wall is compacted, the wall is structurally stable and able to take load, as opposed to a wet-formed concrete wall that typically requires 28 days to reach its design strength. 
The roof is sheeted in a standing seam zinc and tapers towards four 4,000 litre hopper tanks. The architects say that the roof can potentially collect over a million litres of rain water per year which will be used to service the irrigation, domestic and stock uses around the property.
The Equestrian Centre, Merricks by Seth Stein Architects (London) in association with Watson Architecture + Design (Melbourne) is currently being considered for the Australian Institute of Architects Victorian Chapter Architecture Awards.
Wood offers a warm contrast to the pale grey of the rammed earth.
In total the Equestrian Centre has six stables, a feeding room, a laundry area and a tack room. 
Photography by Lisbeth Grosmann. Source: AIA.
Image One: Justin Smallman, Site Plan: Architects. source: Dezeen.
