Print houses will transform the construction industry
Print houses are everywhere – like mushrooms, appearing almost overnight.
Quick to build, many pilot projects test various technical methods and materials.
All of these pilot projects claim four other main advantages: they save on the use of materials, they are cheaper, they require much less labor and they are more airtight (less draft) compared to conventional houses.
The real test of their success will be whether residents like to live there. The companies that crack this problem will be the Ubers of the future construction industry, who rent or sell 3D printers to local franchises.
And the most durable building material to print is… mud. But most use concrete forms.
Due to the current size of 3D printers, most of these prototype houses are about the size of a trailer – a size comparable to the 200,000 “prefabs” that were hastily built in Britain between 1944 and 1950 to provide cheap and quick to solve housing. a severe housing shortage caused by the tens of thousands of homes destroyed by German bombs during World War II.
Manufactured in a precast concrete factory reinforced with steel rods, and assembled on site, these fragile and cold bungalows were only meant to last a decade.
Many actually lasted for decades, sometimes only to be replaced by stronger brick structures that occupied the same footprint. They have always been considered homes for the less well off, but many locals loved them so much that they bought them from the council.
It remains to be seen whether people will love print houses that much.
Printing with concrete
It’s interesting to compare these original prefabs to the home above, assembled from 24 units of concrete ‘printed’ in 120 hours by a machine that ejects layer after layer of concrete at a factory in Eindoven, the Netherlands, then transported by truck to the site for finishing. keys and roof added.
It is planned to build a total of five houses, and future houses will have more than one story.
Like most developers of 3D printed houses, Theo Salet, professor at the Technical University of Eindhoven, complaints they use 30% less materials than traditional construction methods.
But they still use concrete, which has a huge ecological footprint, and as the unit in the photo above shows, they will suffer from thermal bridges.
Printing with mud
These problems are solved by printing with mud. Building with mud is a traditional technique called rammed earth. the WISE educational academy at the Center for Alternative Technology, Wales is a modern use of this method.
An italian company WASP, has now printed a mud house in Massa Lombarda, Ravenna – Italy, using one of the largest 3D printers on the market, BigDelta.
The 323 square foot house, named Gaia, is made with local soil, straw (left over from the rice harvest) and lime. The straw acts as a binder. It is based on “Mud” building, a traditional system of construction across the world.
From a sustainability standpoint, this is significantly preferable to concrete, as it stores atmospheric carbon in the building envelope. The material also has a small transport footprint because the soil is local.
The critical criteria are the drying time (to avoid cracking) and the consistency of the material – which is also a problem with concrete.
Lower consistency leads to poor structural performance: structures can collapse. Quality control is therefore crucial.
To take this into account, the WASP team perfected the mixture to 25% soil taken from the site (composed of 30% clay, 40% silt and 30% sand), 40% ground rice. straw, 25% rice husk and 10% hydraulic lime.
It took 10 days to print the 30 square meters of wall (40cm thick) for a total material cost of just € 900.
WASP rightly claims to have developed a new model of circular housing entirely created with reusable and recyclable materials, sourced from local soil, carbon neutral and adaptable to all climates and contexts. He calls his model TECLA (from Technology and Clay).
Small is beautiful
Smaller homes are better than bigger ones, at least from a sustainability standpoint.
They have a smaller ecological footprint and surface footprint because they use fewer materials and require less energy to heat or cool than a larger home.
3D printing of houses also gives rise to buildings with curved shapes and beautiful geometries, such as this floating house in the Czech Republic.
Another advantage of 3D printing is that the need for formwork is eliminated. The formwork is extremely wasteful of wood and a major cause of deforestation.
Loss of work
3D printing would also decimate the construction industry if it takes off, to which the unions have yet to wake up.
In the United States, Mighty Buildings in California estimates that it saves 95 percent on labor hours, while doubling the rate of traditional construction, and produces ten times less waste.
Their system therefore puts construction workers out of work, with automation replacing four out of five hours of work.
Mighty Buildings uses extrusion printing of an ultra-strong stone composite material that is claimed to be termite, fire and water resistant. Although dirt houses can be made water and fire resistant, termites can be a problem.
Mighty’s Light Stone (LSM) material is a thermal composite that hardens when exposed to UV light and is similar to Corian, a typical kitchen countertop material.
Mighty Buildings claims their process saves 20-30% in costs compared to a traditional pre-fabricated process because the machine prints the entire structural shell of the house, instead of the sections for assembly on site.
Developers Palari Group uses a Mighty Kit panel system, which includes prefabricated 3D printed polymer composite panels shipped from Oakland, to build what it says will be the first 3D printed zero net energy neighborhood in the United States. The houses will be equipped with photovoltaic panels of Solar Tesla and Powerwall.
These will be 1,450 square foot one-story homes. Despite the visual similarity to the post-war homes above, these compare to their minimum area of 635 square feet (59.0 m2) and a maximum width of 7.5 feet (2.3 m) (to allow road transport)
In the future, Mighty Buildings hopes to develop a steel-like fiber-reinforced material that would allow 3D printing of multi-story, multi-family homes for dense urban housing.
3D houses around the world
India’s first 3D printed house was completed in April. This is a one-storey house of approximately 56 square meters located in the city of Chennai, South India, and which took five days to build.
ICON is another company that uses 3D printing to create affordable homes for low income or homeless populations. In partnership with a non-profit association called New Story, the aim is to build a 3D printed neighborhood in Mexico for rural populations.
ICON was the first company to obtain a building permit in the United States for a 3D printed house in Austin, Texas. Its Vulcan II system can print a 74 m² house in 24 hours for less than $ 4,000.
In China, multi-storey apartment buildings were assembled from modules printed by Winsun, which claims to be able to build 10 houses in 24 hours.
Apis Cor, a Russian company, built a 37-square-foot house in 24 hours that costs just over $ 10,000 to manufacture. He also built the “the tallest »3D printed building in the world in Dubai, WATER.
UAE strongly supports 3D printing construction. Last year, he completed the world’s first 3D printed commercial building, a 243 square meter office for the Dubai Future Academy. A 3D printer took 17 days to print the base building, 6.1 meters high, 36.1 meters long and 12 meters wide.
Dubai wants to 3D print 25% of its new buildings by 2025. Given its highly dubious character history of the treatment of migrant construction workers from South Asia, that’s probably not a bad thing.
Chances are, by 2035 millions of homes will be built this way, if the pace of urbanization accelerates as expected.
Of all of the above, the only one I would consider living in is the Mud House. The material is natural and breathable and carbon free, otherwise negative. It is probably one of the cheapest and most durable houses on the planet, in part because at the end of its life it will be easy to dispose of without negative consequences, unlike concrete houses.
And I have also always liked a round house. The only thing is that I’m going to have to buy some round furniture to fit in.