Home comes together 'like Lego'

The concept of the pre-fabricated home has been given a strong environmental twist by Cairns-based Gateway Constructions, a winner in the HIA Greensmart for its Holloways Beach residence.

"The idea has been around for a long time but I don't think it has ever really been successful, until now," says Gateway's builder Jim Margach.

"It took two years of pretty solid research and development with the architect, Gabriel Poole, to get the Takeaway as we wanted it, but now we have a system that represents a path forward for the industry."

Mr Margach believes that the key to success was the builder, architect, and manufacturers worked together, rather than one trying to impose their views on the others.

The result is a manufacturing process that sees the homes pre-built right down to the plumbing, wiring, and internal and external finishes.

Most of the home is flat-packed, loaded into a shipping container and assembled onsite.  The exception is the bathroom, which is built and moved as a module.  "It goes together like a big Lego set," says Mr Margach.  "So far, we have built nearly 40 homes, and we have used our own building people.  They have been involved in the process since the beginning so they know how it works, but there is also a comprehensive manual.  It's logical and clear so any competent building team could do it."

An advantage of the Takeaway is that the design can easily be modified into different sizes, depending on the client's needs.  On average it takes 12 weeks from when the client places their order to when the building is ready to occupy.
"Designing the houses with attention focused on responsible passive solar design enables comfortable living without the need for air-conditioning."  Mr margach says.  "That's a big issue in Cairns, but really it is important anywhere, and is going to become even more crucial, given the direction that government rules about emissions and energy use are moving."

Sustainability features include a "breathing wall" system, and a vented ceiling and roof ridge for funneling hot air away.  Pivoting vents, designed to allow for cross-flow ventilation between rooms, are placed strategically in internal walls.  For insulation, Sisalation paper is installed within the wall cavity.  Mr Margach believes that the sisalation range of reflective foil laminates is one of the most beneficial product ranges for improving energy efficiency and reducing greenhouse gas emissions, and he points to estimates that for every 150 square meter of Sisalation installed as sarking or wall wrap, between 250 kilograms to 500 kilograms of carbon dioxide emissions are saved per annum.

Air-Cell used in the roof space is manufactured without the use of toxic or reactive adhesives.  This means that Air-Cell is extremely durable over time, as there are no foreign properties to react and cause product degradation.

The majority of the home is made from sustainable, eco-friendly products.  Timber framing is made entirely of renewable and sustainable timber resources, and the pre-finished Silkwood timber floor by Boral is also milled from sustainable, managed forests.

Mr Margach notes that all waste from the manufacturing process is transformed into other products.  For example, bark is turned into garden mulch, while peeler cores are machined into pallets.

The Takeaway uses the latest in resource-saving fittings, such as Caroma Smartflush toilet suites, which can save the average home up to 35,000 liters of water per year, and compact fluorescent lights, which are around four times more efficient than incandescent lights.

The design also includes Slim-line water tanks, holding 2500 liters of water each.
Gateway Constructions is currently engaged in the process of having its system patented, and has already begun to explore options for franchising.

"At the moment, the cost of a Takeaway is comparable with homes of similar sizes," Mr Margach says.  "But as demand goes up and we attain more economies of scale, we expect that prices will fall.  The feedback we have had from clients has been positive, and we have no shortage of orders.

"At the same time, we are exceeding the government rules on resource use.  The state government requires an Energy Efficiency rating of three-and-a-half stars, and the takeaway rates as five stars.  So we are getting top marks."