By Gerry McCaughey, CEO of Infineco LLC*

As Americans debate whether prefab is a greener way to build, those active in the discussion should not be surprised when their dialogue receives puzzled looks from their European counterparts.

In Europe, this very question was asked and answered nearly two decades ago. The resounding findings were that prefabrication creates higher-quality structures that reduce both the embodied energy content and the amount of carbon produced annually during the operation of traditional onsite-built homes. The reduction in carbon emissions can be as much as 40 to 60 percent.

Today prefabrication accounts for more than 30% of the new homes built in the U.K. and Ireland and nearly 70% of new homes in Scotland, up from less than 1% during the early 1990s. During that same period, my former company, Century Homes, which later became Kingspan Century, grew from a start-up operation of four employees into Europe’s largest manufacturer of offsite-built structures, producing 8,000 units a year at five manufacturing facilities.

The European Definition of ‘Prefab’

Prefabrication is better known as offsite construction (OSC) or offsite manufacturing (OSM) across the Atlantic.  The European definition of “prefab” differs from that in America in a number of ways.

First, OSC involves the manufacturing of a structure – or even just the building envelope – in a factory-controlled environment using robotics and other modern methods of construction (MMC).  Therefore, OSC is not simply moving the construction of a home under a roof.

Second, any style of a house – not just more modern-looking homes with sleek lines – can be built using offsite construction.

Third, if a house can be built on site, it can be built in a factory at a similar cost when economies of scale are achieved, and to a much higher quality. Construction time is also reduced because MMC can assemble a structure far more quickly and efficiently than can be done by humans.  In addition, sophisticated software is used to “pre-engineer” the building process, which identifies problems that would cause costly delays on a construction site – as well as wasted materials – well before the first piece of lumber is cut.

The European perspective about OSC stems from the widely held belief that there is a direct correlation between higher-quality construction and a greener building and, to that end, higher quality is best achieved in a factory-controlled environment.

This perspective, in particular, runs counter to conventional wisdom in the United States, where homes built in a factory are considered to be of lower quality, which is likely related to negative perceptions of mobile homes.

To those who consider factory-built homes to be of lesser quality, I pose the following question:  If you are buying a BMW – which would you prefer:  one built in a BMW factory or one built by a BMW mechanic using genuine BMW parts in your backyard.

Just as engineering and state-of-the-art robotics have aided the European automotive industry in continually manufacturing higher-quality cars, gains in quality have been achieved when building a house using OSC and MMC.  MMC enhances the structural integrity of a home, because materials are being cut and assembled with far more precision than is humanly possible.

With MMC, tolerances are significantly reduced to less than the width of a fingernail – much narrower than even a saw blade – and nails can be driven into structural materials at the rate of six per second.  When materials are cut to more uniformed lengths and machine assembly ensures that elements are precisely assembled to exacting specifications and further strengthened with the insertion of more nails, the resulting components create an airtight structure, which can reduce heat loss by potentially two-thirds of a standard house.

The Catalyst for Green Construction in Europe

In Europe, careful consideration of how to build greener was a matter of necessity, spurred by the European Union’s signing of the Kyoto Protocol in 1998 and its ratification in 2002.

When the initial 15 EU members entered into the legally-binding international agreement, which committed to reducing greenhouse gas emissions throughout the continent by eight percent of 1990 levels by the year 2012, each country had to develop its own roadmap for reaching their individual target – or run the risk of being named, fined and shamed for failure.

For many EU countries, the planning process for reducing carbon quickly turned to how to build more sustainable and energy-efficient residential structures, as in the mid-1990s homes accounted for approximately 25 percent of annual carbon dioxide emissions.

In particular, both Ireland and the United Kingdom were forecasting a significant boom in housing starts.  The Irish government was forecasting that the number of houses built annual would increase from 22,000 to 90,000 during the next 10 to 15 years. In the U.K., the number of residential structures was projected to rise during the same period from 160,000 to 250,000.

Unless pragmatic plans were developed to address residential energy efficiency, leaders for both these countries recognized that the increase in housing units would seriously undermine efforts to reduce carbon emissions.

Ireland responded by raising energy-efficiency standards by 40% in 2008, which was followed by an additional increase of 20% in 2010.  It also began requiring that every new home must provide 15% of its energy use by onsite renewable means.

In the U.K., legislation was passed requiring that all new public or social housing be carbon-neutral or net-zero energy by 2013 and new private homes by 2016.

The British government also implemented a number of initiatives to encourage increased use of OSC and MMC. One such initiative was a challenge to build a house using offsite construction that would meet the 2016 green-building standards.

In response to this challenge, my former company built “Lighthouse,” one of the world’s first net-zero energy houses, which was unveiled at the Building Research Establishment’s premier event in 2007. The estimate annual cost to heat Lighthouse – in the temperate maritime climate of the United Kingdom – is approximately $80.

Paving the Way for More Sustainable Building

In order for mainstream U.S. builders to embrace more sustainable residential building, either the federal government or individual states will need to develop energy-efficiency standards for new home construction. As part of these standards, consumers should be provided with information on how much it will cost them annually to heat and cool their homes.

In Europe, as part of the Energy Performance of Buildings Directive (EPBD), every home, and not just a newly constructed home, that is being offered for sale or rental must have an Energy Performance Certificate. This legally binding document discloses the structure’s annual energy costs and CO2 emissions, while also providing suggestions for how the home can be operated in a more energy-efficient manner.

Just as customers are armed with information on the fuel efficiency of any new car purchase that they are contemplating, providing estimates of annual heating and cooling costs would enable them to effectively evaluate to what level of energy-efficiency a home has been built.

And once transparent energy-efficiency standards are in place in the United States, the many sustainable advantages of offsite construction will become readily apparent.

*Gerard McCaughey is Chief Executive of Infineco LLC, a firm specializing in providing executive-level services to U.S. businesses developing and funding emerging green technologies related to both sustainable building and renewable energy. Mr. McCaughey previously co-founded Century Homes, Europe’s largest offsite building manufacturing company with five plants in Ireland and UK, which he sold in 2005 to Kingspan Group Plc. He is generally regarded in Europe as being one of the leading figure in the green building movement, and was at the forefront of regulatory reform in both Ireland and Britain. He has spoken and written about green and offsite construction in many countries around the world and is a previous winner of Ernst and Young’s Industry Entrepreneur of the Year Award.

Photo credit: Kingspan Century.