Polyurethane for emergency and prefabricated buildings and construction

The world needs housing. Population growth, global migration and refugees contribute to this need. Jane Denny found out how polyurethane can help.

The International development charity Habitat for Humanity estimates that nearly one out of every four people in the world live in substandard housing. Homelessness affects 100m people, it said.

The United Nations says 1bn people – almost a third of the global urban population live in slums, and that could double by 2045, it said. Meanwhile, over a million people are born to, or choose, city living in the developing world each week, the organisation said.

Worldwide estimates for displaced persons due to conflict, war and persecution at the end of 2014 was 59.5m – up from 51.2m a year earlier, according to the UN’s High Commissioner for Refugees. In other words the same number of people who live in New York, or Madrid and Berlin and Rome were displaced in that year.

Natural disaster displaced over 40m people in 2010, half that number in 2014, according to Switzerland-based agency the Internal Displacement Monitoring Centre.

There is considerable pressure on society to build more good quality houses and shelters quickly and cost-effectively.

This is a challenge that PU can help the world meet.

PU emergency shelters

Students in France have come up with a potential emergency housing solution – a shelter that can be created in minutes from polyurethane and last for months.

Using polyurethane and a robotic 3D printer with a 3m² capacity, a team from the University of Nantes in France can produce a shelter in under 30 minutes.

Alongside the university’s commercial business, the student team is now working on a second machine with capacity for 7m² shelters, INNOprint version two.

Benoit Furet, a professor at the university’s Research Institute in Communications and Cybernetics, said he imagined that, in a disaster, the robot will be shipped together with raw materials in containers.

“There, on demand, according to the desired size and within 20 to 30 minutes, an emergency house could be made then used for several months,” Furet said.

Give me shelter

While the future may look to France, Turkey has provided concrete examples based on polyurethane sandwich panels.

Istanbul-based company Karmod uses polyurethane sandwich panels to manufactures shelter standard accommodation.

Within a seven-month period in 2012, the company built more than 1,800 housing units in Baghdad and Kut, Iraq.

Karmod claimed at the time it was “the world’s largest prefabricated housing project” and the firm proved that from a 20,000m² facility it could use a “polyurethane container model to create emergency settlement units by mass pre-production and within a short time.”

“Polyurethane sandwich panel containers are best used as living containers for quick and safe solutions after any unforeseen natural disaster,” according to Karmod.

Karmod claims that its emergency settlement PU sandwich panel shelters are earthquake proof up to Richter 7.1 – the magnitude of a 2011 disaster that left 60,000 people homeless.

Instacon= 10 floors in 48 hours

Polyurethane prefabricated buildings are not restricted to shelters.

In 2012 Indian company Synergy Thrislington built a 10-storey residential building – Instacon,  short for instant construction - in 48 hours.

The structural shell of Instacon – located in Mohali, Chandigarh, about 200km north of New Delhi in India - is made of steel and covered with double-skinned PU foam panels. Total construction time from foundation digging to final fixtures and fittings was three months.

Synergy Thrislington’s chairman and md Harpal Singh – a 2013 Sikh Awards business category winner - divided each floor into four blocks or modules of 3.9m by 15.8m. The modules were pre-made at a factory, transported to the building site and then assembled onsite.

Synergy Thrislington – previously a UK business – has an 18,000m² manufacturing facility in the Nalagarh, Tehsil district of Solan. Its main business is in PU panels. Mr Singh has a continuous line to manufacture PIR insulated sandwich panelling.

The continuous PIR is then cut down to size. The panel’s skin is a PVDF coating. Instacon’s inner structure is made steel. His company now has more than 10 Instacon buildings within India.

He told Urethanes Technology International magazine he developed the machine himself and thought about insulation when India “did not have a concept for insulation.”

He has been working on the project for three years.

He said he came up with the idea when he was building one of his hotels in India. That project took 14 months, he said, which is much faster than the three years most construction projects of that size can take.

He said his modular system is advantageous due to ease, speed and the energy efficiency of PIR insulated panelling. That said, he expressed a degree of disappointment at the uptake of his vision for India’s housing solution.

“I developed the concept thinking I’d be building hundreds of Instacons. For me 14 or so buildings is pretty slow.” However, he did say he felt a four to five year period would be ample time for the idea to stabilise in India.

The PIR system’s “maximum insulation for minimum thickness” was why Singh chose PU building material but durability was also a factor, he said.

Singh estimates that with a Richter 1.7 earthquake, 90% of houses will be demolished. He said the Instacon building was tested at India’s Structural Engineering and Research Centre – a constituent unit of India’s Council of Scientific and Industrial Research, over three months. Singh claims the Instacon building will last 100 years.

“I do 70% of the work in the factory and that can go on 365 days a year. If you are looking at housing on a mass scale that is the only way.

“A building made from bricks and mortar can never get the quality that you can get in a factory. A house made in a factory is 100% accurate. Everything is in the right place from day one.

“On-site buildings of bricks and mortar are susceptible to the elements, which can cause problems that go undetected at the time but return later. Weather factors can also slow down the construction process.

“Three issues: time, cost and quality. The moment you begin to tackle the housing issue this way, you make the cost of housing go down and we have a 26.8m housing shortage in India. This is a challenge you can never meet with bricks and mortar.”

The 2,553m² building was put together using three cranes and around 200 technicians and workers – and was recorded as a record in a number of record books for speed of construction.”

Dome sweet home

In the US, hemispherical constructions using a polyurethane core to create large buildings like schools, sports and community facilities as well as family homes are finding favour. Modern day dome buildings were the brainchild of David South, of South Industries and his two brothers who between them run three companies serving a worldwide market for monolithic dome structure building.

South Industries began as a PU foam company until, with the help of a Brigham Young University professor Arnold Wilson, a system was formulated for creating dome structures using a three inch inner layer of PU foam. The outer layer is concrete – a sprayed material known as shotcrete.

There are currently around 30 schools in the US based on the South brothers’ design, community facilities as well as sports halls and homes have been built worldwide.

The domes meet US protection standards set by the Federal Emergency Management Agency and, said South, “have a proven ability to survive tornadoes, hurricanes, earthquakes as well as most manmade disasters, fire, termites and rot.”

He said: “They are cost-efficient, earth-friendly, extremely durable and easily maintained. Most importantly, a Monolithic Dome uses about 50% less energy for heating and cooling than a same-size, conventionally constructed building.”

Tiny but perfectly formed homes 

Polyurethane is also at the heart of the tiny house movement in the US. In November 2015, the American Chemistry Council (ACC) gave the mobile home concept a polyurethane makeover when it worked with partners to create a home as part of its Plastics Make it Possible campaign.

The living space uses Dow Building Solutions’ spray foam to plug gaps in the construction and improve the structure’s energy efficiency. Dallas, Texas-based Rmax’s Thermasheath polyisocyanurate foam boards were used under its siding, which reduce the need for heating and cooling measures.

Covestro’s PU-based fibreglass, with a PU foam core, make up the house’s door.

Idaho-based Ray Core SIPs were used by Maximus Extreme Living Solutions (image 5) to build a similar small home in 2015. The energy-efficiency of firm’s SIPs already confirmed by their use in a Toronto, Canada-based Passive House in 2013. Once completed, a Blower Door test – an analysis of the building’s capacity for leakage was 50% better than the European Passive House standard, according to RayCore. Maximus’ mobile home was designed to counter temperature swings from -45 to 65 °C (-50 to 150 °F). Ray Core also supply SIPs for more traditionally-styled homes (SEE image 5)

The living space measures 7.3m by 4.2m by 2.6m and includes a loft unit for sleeping, bathroom and kitchen area. It has a total floorspace of 31m².

 Modular homes save time and money

Research by McKinsey Global Institute shows potential for a 30% cost reduction in off-site manufactured modular building methods using products such as structured insulated panels.

Off-site production can strip up to 40% off building schedules against traditional building methods, the organisation’s report A blueprint for addressing the global affordable housing challenge, found in 2014.

Furthermore, removing elements of the process from unconnected contract teams removes some of the margin for error in construction.

The added accuracy of dimensions that comes from automated production of the materials for materials is a key advantage for UK-builder Andrew Rowe, from Lincolnshire, England.

He built 50 homes using traditional brick and block construction but after building a SIPs home for his family he said SIPs allowed groundworks to moving in schedules of 16 weeks.

“In addition, panels are so accurately made that I have been able to order windows off the plan and they all fitted perfectly,” he said.

SIPs-constructed housing can cut up to 60% of energy consumption, due to the insulation and heat loss qualities of the method.

Sips can be used for walls and roof. With SIPs the shell element of a two-story family home can be constructed in less than a day with a team of around half a dozen people.

Mooresville, Indiana-based SIPs company Thermocore uses BASF’s PU technology for its SIPs (see image 6) and has supplied a range to builders keen to work with modular designs and techniques. The company said modular systems can be installed onsite in less than 24 hours.

Prefabs are Fab! 

According to New York-based insurer Hiscox, the next decade will see a pre-fab renaissance. The next-generation pre-fabricated homes will be well-engineered, factory built homes that improve affordability and help relieve housing shortages, according to a report by the firm.

Hiscox’s quantitative research was conducted online with a total sample size of 3,000 nationally representative people in France, Germany and Great Britain (1,000 per country). The research was carried out in April 2015.

The company’s Home of the Future report claims that, as it is, a quarter of Germans and a third of Britons are interested in this type of home - particularly young people.

Support is higher among young people – for example, over half of French people aged between 18 and 24 are interested in prefabricated or kit homes. Interestingly, there is no significant difference in the level of interest in this type of housing between higher and lower wage earners.

Global shipments of prefabricated housing are projected to reach 1.1 million units by 2020, according to a report by California-based research agency Global Industry Analysts.

Johannes Schworer, president of the Federal Association of German Prefabricated Housing, said: "We are experiencing a high demand for prefabricated houses, which is reflected in rising unit sales and market share."

According to Schworer, 9,834 building permits for prefabricated houses were granted between January and July – 7.5% higher than the same period in 2014.

For comparison: A total of 59,752 permits (previous year: 58,674) were approved for new homes of all construction types. This is a slight increase of 1.8 percent. Accordingly, the market share of prefabricated buildings rose to currently 16.5 %(previous year: 15.6 %) in the nationwide average.

In regional terms, this market share very unevenly distributed: Baden-Württemberg has 28.8%, the highest, Lower Saxony with 7.0 %the lowest prefabricated proportion of all federal states in.

Sales of the 45 member companies of the association, which cover about 90% of the West German market, was 1.87 bn euros in 2014. For the full year 2015, the association expects a revenue growth of 4.2% to be EUR1.95 bn.

In the US, according to GIA (Global Industry Analysts), shipments of prefabricated housing within the country is expected to 133,000 by 2020. Favourable federal housing policies, national efforts related to the supply of affordable housing and the provision of monetary, legal and tax-breaks for modular similar to conventional construction methods are helping to drive the market. Single-section manufactured housing is expected to grow at 5.4% CAGR to 2020.

GIA said Japan represents the largest market worldwide with the Asia-Pacific region.  But China ranks as the fastest growing region with a projected CAGR of 9.3% from 2014 to 2020.

Housing need worldwide

India’s National Democratic Alliance, a political group which controls India's lower house of parliament wants 30m new homes by 2022. South Africa’s target is 1.5m houses before 2020 while the Brazilian government is in the process of a 3m-home construction project, which was due for completion at the end of 2015.

In the Middle East, there has been a massive rise in the need for temporary housing due to ongoing conflicts in the region, which have left many millions displaced.

Although the poor and displaced make the headlines, this is a first world problem too. The UK government wants 1m new homes built by 2020 due to what the country’s House Builder’s Federation calls a “chronic housing shortage”. The federation says the country requires at least 220,000 new homes a year to meet demand – without touching historical undersupply.

In its September budget, Sweden’s government pledged to contribute towards achieving the target of 250,000 new homes in that country by 2020. Meanwhile France’s target is 500,000 new homes a year over five years. Given the willingness of European Union member states to accept refugees in recent months – Germany expects 800,000 asylum seekers this year - some estimates put it as high as 1.5m, more housing and shelter is going to be required both short-term and long term.

Mass migration to Europe will only exacerbate the need. Thousands arrive at Eastern European countries such as Croatia, Greece and Turkey from conflict zones in the Middle East.

Solutions using polyurethane have been emerging for both the emergency shelters for displaced peoples both within the Middle East and Europe, but also to meet the housing needs of growing communities in developed countries.