Contour crafting, a new model for building construction that combines large format 3D printing technology with automation, has been under development since 2004 and was introduced to a wider audience by Dr Behrokh Khoshnevis (University of Southern California) through a TedX talk in 2012. In 2014 Win Sun Engineering in China unveiled ten 3D printed houses, houses that had been built in 24 hours, made using a mix of fast drying cement and recycled waste material. WinSun has recently received an order for 20,000 residential units from the Egyptian government and videos from the Chinese builds have over the last year gone viral to spark the imaginations of makers, architects, entrepreneurs and engineers all over the world.
For decades modern day buildings and landscapes have been drawn by means of digital tools while the actual production has remained in labor intensive and manual trade. Various materials are transported to and assembled by different specialists in a predetermined order over months of work on site. There are strong economical and environmental arguments for innovating the construction industry and looking at ways in which processes can be further digitalised and automated. In 2009 the cost of producing buildings in UK was consumed by 70% labor; leaving only 30% to physical construction/material costs according to researchers at engineering firm AKT[1 ]. Production of buildings and landscapes and the transportation and cultivation of conventional construction materials hold the largest carbon footprint of all sectors in the western world today; this alone indicates the importance of addressing not only research in the 3D printing technology, but also the actual materials/pastes used by these technologies. Traditional means of building and landscape production leave as much as 15% of the materials used as waste either on site or as part of the mass-customization processes previous to site work. In Sweden 10% of energy is consumed by the construction industry[2 ]. Digital manufacturing can hugely diminish the abovementioned labor cost, while also excluding dangerous aspects of manual construction (construction work is one of the most dangerous professions in the developed world- more hazardous than fire fighting or mining). In contrast to human workers, automated machines can operate 24-7, almost regardless of weather, and can perform many tasks with more accuracy. There is money saved on materials through less waste and smarter application. The speed of construction also saves money on financing as the need for credit is reduced. Savings in time and downsizing of heavy machinery and trucks also has a positive impact on the surrounding neighbourhood, in terms of less disruptions in traffic and noise around the construction site. Finally, there is less energy consumed and less need for transportation of material- and this, of course, has environmental as well as economic benefits.
As we go from mass production to mass customisation, and from pre-fabrication to fabricate-on demand, this new logic means that standardised bricks, pieces of cut wood and steel beams may no longer have their central place in construction. Apart from the impact on production of conventional materials, new materials are being developed- materials superior not only due to their usefulness in additive manufacturing but with superior properties in terms of, for example, durability. A 4mm layer of 3D printed nano-gel has the insulating effect of a 400 mm thick wooden board, and a concrete mix containing nano-carbon tubes is five times stronger than conventional concrete which enables lighter and thinner constructions. Many of these new materials also have the advantage that they can be ground down and recycled. One tickling scenario is how 3D printing can enable the use of hyper-local materials. This is being developed by NASA and the European Space Agency who are looking to 3D print extraterrestrial bases by using available material on site (eg lunar soil)[3 ]. Imagine in this way being able to make use of an old building that is being torn down, directly on site, in the new construction. Organisations such as DataClay, EarthArchitecture. org and WASProject look at ways to fuse digital technology with traditional methods of earthen constructions, using 3D printing to create mud buildings that have minimal environmental cost[4 ]. Another interesting area of opportunity is the combination of additive manufacturing and so called 4D materials where the 4th dimension is time. Materials and structures can be programmed to react to their surroundings in smart ways. New technologies can also fuse materials by combining nozzles, materials and techniques, in order to print structures which instantaneously contain all the required functionalities from insulation to cladding to electronics enabling smart functions (IoT). Applying this to architecture and construction, we can imagine walls that open on a hot day, solar panels that twist like flowers to follow the sun, or materials that alert us to and counteract pollutants and hazardous materials in our surroundings.
'For centuries, our design thinking has been shaped by our manufacturing tools. We still think in straight edges and sharp corners, because these were usually easier to produce. But not anymore. I often remind my students: If there is a straight edge or a sharp corner in your design, it's probably not optimal. Show me a straight edge or a right angle corner in nature.' -Hod Lipson
In areas tormented by earthquakes, modern buildings crumble while some ancient cob or adobe structures stand the test of time due to their curved geometries. Rectilinear walls are the worst structures as far as strength is concerned. The structural advantages of a curved wall can easily be illustrated by holding a piece of A4 paper and attempting to get it to stand straight. New software is being developed which allows much more effective simulation and structural assessment, and which is also more user friendly, thus paving the way even further for non-standardised geometries in construction. Some use these new design tools and technology to propose a new aesthetic based on integrating functions and components into a surface, putting forward a new type of minimalism.
Others, like Michael Hansmeyer and Benjamin Dillenburger revive a heavily decorative style in their project Digital Grotesque, a large 3D printed piece reminiscent of gothic baroque, premodernism.
The potentials of additive manufacturing in architecture are enormous. Architectural details can reach the threshold of human perception. There is no longer a cost associated with complexity, as printing a highly detailed grotto costs the same as printing a primitive cube. Nor is there a cost for customization: fabricating highly individual elements costs no more than printing a standardized series. Ornament and formal expression are no longer a luxury - they are now legitimized. With additive manufacturing, architectural design can be performed entirely in three dimensions without a need for plans, sections, and construction drawings. There are almost no fabrication constraints. With this technology, the scale for the designer has shrunk from bricks to bits. Architecture can be defined at the scale of sand corns, materiality can be synthesized
Opportunities afforded by digital software, digital fabrication and mass customisation must be embraced by policy makers unless we want planning and building regulations to stand in the way of innovation and of cheaper, better, more sustainable and diverse buildings.
Alongside industry, the maker movement has been instrumental in pushing the development of new cheaper more effective and user friendly machines for digital fabrication, open source software and new materials. In the realm of built environments, giving new digital tools for design and fabrication not only to architects and engineers but to home makers and DIY-ers has the potential of jump starting innovation, with new techniques and materials that can be of interest beyond the do-it-yourself and doit-with-others sphere, innovations that may influence construction on a larger scale. Enabling the masses to construct living environments may be a key factor in solving the housing crisis connected to rapid global urbanisation. An inspiring example of this is The Good Half House by Elemental, led by architect Alejandro Aravena and started in 2001 in Chile. In this project, Quinta Monroy, Aravena was asked to come up with social housing in Iquique for 93 families on the site where they had been squatting for the last 30 years. This with a budget of just US$7,500 per family. Elemental worked with the families themselves in participative workshops, proving feasibility on a local level. The conclusion of this process was that instead of building smaller version of good houses, half of what was considered a good house was built, containing the pieces that were most difficult for the home makers to construct on their own. By a clever design that made possible the easy extension of these houses the families were then able, by themselves, to double the square meters of their initial homes (36 square meters) for only US$1.000 each. 5 years later, any house in the Quinta Monroy project was now valued at over US$20.000 and each home had been customised to suit the needs of the people living there
The smart cities of the future are imagined as an internet of energy where each household produces energy and value which it can sell back to the grid. In this new sustainable economic system we create the energy we need locally, take care of our own waste and eliminate transportation. Environmental concern and a critique of, and the attempt to change, current systems of trade often go hand in hand with the maker ideals. All over the world, one way in which makers are paving the way, is by building so called 'tiny houses', and going 'off grid' to escape debt and dependency on fossil fuel and to live a sustainable lifestyle with less clutter. The knowledge generated in these builds is spread through blogs, downloadable files and other types of blueprints freely available for non-commercial use.
Linnéa Therese Dimitriou is Creative Director at Sliperiet
 AKT Engineering Firm, London 2009
 'Bygg- och fastighetsbranschens miljöpåverkan" by KTH and Statistiska Centralbyrån, commissioned by Boverket, 2014
 www.eartharchitecture.org, dataclay.org, www. wasproject.it
 Hod Lipson, 3D Printing and Manufacturing, Vol 1, Issue 4
 Prof. Behrokh Khoshnevis, TedXOjai 2012
 The Third Industrial Revolution; How Lateral Power is Transforming Energy, the Economy, and the World, Jeremy Rifkin, Palgrave MacMillan, 2011