Bush-Craft

ARKit’s design for a holiday home at Wye River on Victoria’s Great Ocean Road is a model of modular intelligence. Viridian double-glazing enables the design to be brilliantly alert to its setting.

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As far back as 1852 pre-fab cast iron houses came to Australia from Britain. Stately examples such as Corio Villa on Geelong’s waterfront were remarkably ahead of their time. Henry Ford re-defined the possibilities of mass assembly in ways beyond the reach of today’s construction industry. The push for prefabrication is now advancing around the globe with the factory floor winning recognition for quality control and on-site savings. Companies such as the Melbourne-based ARKit whose punchline ‘Advanced Prefabricated Architecture’ provides a potent alternative to the conventional build.

The firm’s design for a holiday home at Wye River on Victoria’s Great Ocean Road is a model of modular intelligence. Viridian double-glazing enables the design to be brilliantly alert to its setting.

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Vision’s Peter Hyatt spoke with ARKit director and founder Craig Chatman about a system he hopes is an exemplar of build quality and environmental relationship.

How did the Wye River House come about?

Our clients were committed to a building that blended with its environment. There was a desire for concealment, or camouflage, that we followed right through the design stage. That idea of connecting with the landscape was realised in the timber and glazed facade. We had to technically come up with a construction system that would ensure the facade was bushfire ready. The visible facade timber is a sacrificial layer behind which is a one-hour bushfire rated system. The house has retractable metal external screens that also cover the double-glazed windows and doors.

How else does this design vary from your typical city, or rural, prefabricated designs?

This is our first experience with such a setting, so there were certain unknowns, but nothing too challenging. Complete buildings typically leave our factory as virtually completed modules and are assembled on site. On this project the modules were a little too big for transportation along the Great Ocean Road and involved extra on-site assembly.

What about delivery to such a remote site?

The major components were delivered and then craned into place. We minimised the usual pre-fabrication build to reduce bulk for transportation. Everything was flat-packed, or panelised. We monitor construction costs from the schematic design stage through design development and documentation stage. We would usually spend more time on-site, a little bit less time in the factory. The panelised system of floor, walls and roof produces a precise fit on-site.

Are there any other differences from your more typical pre-fab and assembly?

Most of our designs are based on a grid largely because most materials are available in certain widths and lengths. We utilize those economies to the benefit of the project but outside of that it’s a pretty open book. We’re not too constrained by widths because we can join volumes together.

Pre-fabrication or modular construction appears to be gaining real momentum but isn’t there still a lingering prejudice against it?

Hopefully these projects help address those perceptions. Our materials are at the premium end and factory assembled under tightly controlled conditions. Certainly it’s of a higher standard than a typical builder could manage on-site. We use engineered products wherever possible. Because our assemblies undergo a certain amount of stress during transportation and craning, they are almost over engineered.

How does your ARKit system measure up in cost against the standard build?

Our system compares pretty well. Our real advantage is a superior quality build. There are tight tolerances in our factory and time-savings that avoid the typical on-site issues. Although this was a partially on-site and factory build, the construction program for the whole project was around five months – including difficult winter conditions. Built conventionally, stick by stick and given the issues of Wye River and site access, it would have taken around 10 to 12 months to construct. While the cost is comparable, our build quality is definitely superior.

What do you consider is the design’s main strength?

The way it blends into the landscape. It really fits beautifully. Our approach was to never dominate its setting, but see it concealed within the landscape.

Some building designers resort to maximize the wall area in an attempt to better manage interior temperatures and so really minimize the role of glass with a subsequent loss of amenity. You manage to retain a generous expanse of glass and achieve an excellent thermal performance.

We had to respond to the site and setting. Anything less would have been a travesty. It has beautiful filtered views towards the surf-beach and we needed to capture those south facing views.

Along this main approach elevation there’s a big expanse of glass on the west-facing balcony. Do you differentiate between how we typically consider what are windows and doors?

Not really, but it’s a good question. No, we look at the openings as being apertures. There’s a hierarchy between what’s a window, what’s a door. The doors and windows are generally full height on the southern and western elevations so there is a certain breaking away from the standard framing system.

Does the glazing perform anything else apart from the obvious to capture those beautiful views?

It adopts a commercial language whereby the project specifically uses a commercial language where it acts as a spandrel panel and glass conceals the building’s structural elements. On the eastern elevation we run the glass from the underside of the building all the way to the top of the parapet.

You appear to have performed some fancy footwork with the structural and glazing connections.

Where the sub-floor and roof structure meet, we’ve painted the back of the glass in a form of ceramic paint for an effect not unlike a kitchen splashback. This gives the illusion from outside of this fully reflective, immersive environment without any opaque wall below or above each window. This results in a window wall that runs the full height of the building.

You’ve opted for Viridian double glazed units (DGU’s). How important are those to maintain overall design and build integrity?

They are absolutely integral. We also achieved a high thermal performance without compromising the opportunity to bring the environment right into the heart of the house.

What pointed you towards Viridian?

In our experience people such as Con Kantis at Viridian provide a really helpful level of engineering and product specific architectural input. It’s not so much about just buying glass, but receiving that technical back-up and attention for the details and elements to ensure these are the best they possibly can be.

Design is rarely predictable, the prototype more so. How does this stack up to the renderings and computer-generated graphics?

You stand inside, look out and there’s an unexpected integration with the bushland setting. The ceiling reveals itself in unexpected ways in that it folds back with the ceiling height rising from 2.7 metres and then cranks back up to 3 metres high on the outside edge. So that was very pleasant and far better than I would have expected or anticipated.

Because of the way glass integrates and provides a rising panorama into the forest canopy?

Yes. It’s almost as if the ceiling is a floating object and the glazing extends beyond that and becomes a huge, south facing aperture.

How obvious a choice was Viridian’s double-glazing?

We only use double-glazing. Their windows and doors definitely add to the general environmental building performance and long-term project value.

It’s almost a re-take of Ned Kelly’s visor with this horizontal vista that really takes you into the bush and connects. It’s not an apology for what might have been.

We’re fortunate because we don’t overlook neighbours where the best views are. The window on the eastern side is a little more restricted. The northern edge creates a closed down, or bunker effect at the rear, north-facing elevation.

What window system have you used?

There’s the two and a half metre wide sliding door on the western patio and a similar door south. Bedrooms on the southern edge access the balcony along the southern side. One of the reasons we used Element Windows is the high quality, top mounted mechanisms that slide so easily.

What are some of the other design possibilities you see for the ARKit system?

ARKit has designed and built projects as diverse as a Fire Tower, an office building for 20, a four storey mini tower, a couple of early learning centres along with our variety of residential projects. Our panelised construction approach is being expanded into a solution for indigenous remote communities. It is a bright future for offsite constructions with PrefabAus aspiring to an increase from 3% to 10-15% of residential building construction projects in the next five years.