History has shown in several instances that rising complexity in building & construction technology is a marker of advancing civilisation, more complex building technology and building maaterial signifying more recent development. This phenomenon is as a response to the evolving human individual and public needs of each era, no matter how slow such evolution seems to be in comparison with other industries. The 21st century is no stranger to far ranging developments in practically every industry. The building construction and design has not been untouched by the advent of revolutionary technology most evident in the last four to six decades. Mechanisation has taken an upswing to give room for information and communication technology (ICT), machine learning, deep learning, digital modelling and simulation and artificial intelligence to the hitherto traditional building technologies. 

Hitherto traditional forms of building construction (such as woodwork, masonry, bricklaying etc) have been criticised for its several flaws as being offshoots of archaic methods; the long, time-expensive procedures and bureaucracy, waste, high and still rising costs due to inflation, labour inefficiency and the large number of manual labourers often involved in such building projects, the lack of a guarantee in design and structural quality, the high rate of accidents and fatalities recorded on construction sites, overproduction as well as harmful impact to the environment. The latter is often due to the extraction of non-replaceable raw materials from the earth and subsequent depletion of the Earth's resources; the energy-inefficient manufacturing process; the shipping of raw materials; the use and potential toxicity of such materials and the resultant increase in carbon emissions are a factor in the climatic changes that have occasioned the issues we've seen today. 

Though the architecture and construction industries have seen significant impact due to technology, it has mainly been in mega, commercial construction. Technological growth in the individualized, day-to-day small scale building construction hasn't been a lot (apart from mechanisation and the greater use of hand-held power tools) due to deeply rooted paradigms and practices. The need for sustainability in building construction and design processes in individual and public infrastructure (individual and mass housing, bridges, offices, prisons, hospitals/morgues, public service infrastructure etc) vis-a-vis the growing rate of urban migration and development has necessitated the incorporation of innovative, creative new technologies that show the potential to become the foundation for the buildings of the future. 

Of this spectrum, Building Information Modelling (BIM) and 3D printing are two technologies that have recently changed the way structures and building components are designed, fabricated and constructed.

Building Information Modelling (BIM)

Building Information Modelling (BIM) is one of the more modern, promising and recent devlopments affecting the architecture, construction and engineering industries, mainly due to its multifunctional and multipurpose nature. 

Building Information Modelling has been defined as "a modelling technology and associated set of processes {involved in} to produce, communicate and analyse building models". It's also been described as a new software that helps describe and display the design the information required for the design, construction and operation of constructed facilities. 

Although there isn't a universally recognised definition of what BIM is, it is agreed that it is a way of designing, constructing, operating, managing and maintaining a structure that allows for collaboration between all stakeholders involved in all of the above processes. Beyond being described as a singular action, digital model, software application or an intangible concept, the reality is that Building Information Modelling is a process that combines information, communication protocols and technology to create a digital representation of a project and is designed to generate and manage building data from the earliest stages of conception to design, through construction to demolition of the project. It does this by the construction of an accurate, virtual model with the physical and functional characteristics of the facility itself and monitoring such throughout the the buildng's life cycle. The Information part of BIM comes into play here through the creation of a shared, collaborative knowledge bank containing every relevant fact about the project, such as design details; geometric and non-geometric progress information, construction components and materials, and maintenance schedules that provide a basis for any decisions that are made during the entire life cycle of the project. A BIM would typically go through progressive iterations throught the project life cycle. The Project Information Model, which demonstrates design intent is the first form of the model. Then this is developed and further refined into a virtual construction model and finally becomes an Asset Information Model, developed for use within operation phases. All of these models demonstrate the fluid flow of data use. 

One of the biggest advantages of BIM software is that it allows for structures to be virtually modelled, before being physically constructed, thereby enabling necessary analyses, sequencing and improvements to be made to the project in a digital environment,which is considerably cheaper than making such changes in a physical model. Its ability to facilitate collaboration between all project participants and stakeholders; grom the architect down right to the investors and governments. The exchange of information and knowledge and free flow of communication allows for timely improvements and adjustments of the design scheme, which in turn creates a better end product for the user. If the data created is not shared and communicated effectively, then the model cannot be regarded as being a Building Information Model. The Open BIM approach is what allows for the exchange of information in BIM. Here, data and linked project documents, that would otherwise have no relative value if not shared, are exchanged through technologically transparent standards and workflows. Open BIM allows for universal project participation for members at all times, creates a common language for usage, prevents multiple inputs of similar data and provides an enduring building data bank that can be used as a reference point throughout the asset's life cycle. 

When combined with technologies like 3D printing, the BIM technology has significantly greater impact than when used alone. 

3D Printing in Construction 

Generally, the advent of 3D printing has been avowed as one of the greatest technological advances made in the 21st Century has found progressively popular usage in many industries, from transportation, aviation, healthcare, gene research and technology, automobile engineering, architecture to art. Although the construction industry has been largely impervious to technological inventions advanced over the last century or so, 3D printing is currently being explored as a veritable medium to explore alternative methods of building construction and design. 

3D printing technology allows for the creation of three-dimensional, physical images and objects by superimposing successive layers of materials, directly from a digital model. In 3D printing, a digital model is created using software; the model is then sliced into layers which are laid on top of each other to create a tangible object (as opposed to just a representation) by means of a 3D printer, all in a highly automated process. This technology gives users the ability to create objects based on highly personalised models and accurate, without requiring nything other than the component materials required for the creation of the designed object, this preventing waste and reducing cost. It must be noted that 3D printing processes require software, hardware and component materials to create a 3D printed model. Different types of 3D printers employ different technologies, which process different materials in different ways. 

3D printing in construction is known as additive manufacturing or additive construction, and utilizes advanced technology through highly automated processes to manufacture construction elements by means of a 3D printer. Given that the most popular construction material is concrete, which is easy to source and maintain, and relatively inexpensive, 3D concrete printing technology is a developing iteration of 3D printing technology that is applied in concrete construction. A predefined construction element in a digital model is manufactured; the concrete is then poured through a printing nozzle that does not need any forwork or subsequent vibration, this minimizing waste and reducing costs. 

The technologies of Building Information Modelling and 3D construction printing are, individually, great boons to the construction industry, as they assist construction practitioners in enhancing the quality of industrialised, residential and everyday construction. However, taken together, they are a powerful force that hasten the arrival of the building of the future. 

Integration of BIM and 3D Printing

Building Information Modelling is an Information and Communication Technology empowered tool that can be synchronized with 3D printing assembly to create efficient buildings at a faster rate. The combo of both technologies is a relatively new approach that, when carried out accurately, takes fully the advantages of each system to create a unique building methodology that has the capacity to form unconventional and highly complex structures, small or large scale, with great efficiency and less effort. 

In this new approach, the BIM software creates a digital model (made to user specific/exact user demand requirements as to design, planning and construction) and feeds the data (algorithmically, via its data workflow and fluid data transfer) into a 3D printer. The BIM software provides the building model information and the printer follows the path. The BIM data is converted into a code that can be read by the 3D printer, also with the aid of software, in order to realize the production process. Through BIM software, the printer can realize changes or errors in real time and improves the visibility of the graphics of the objects in the model without having to restart the code or split the design into different files. After the path has been completely laid down, the 3D model is visually displayed for any further modifications, improvements or monitoring. 

In 3D concrete printing, robotic technology is utilized to improve the quality of the final product. Usually in form of an arm, the robot is equipped with a nozzle which is fed with the construction component material (in this case, a concrete and composite mixture, usually thicker than regular concrete), and extrudes it in layers and layers according to the specific dimensions of the input code, directly generating the actual building or component parts that are to be made. Real-time data can also be transmitted through the BIM system to achieve a dynamic management process for the purposes of quality control. 

Advantages Of BIM & 3D Printing Integration

• Accuracy and Flexibility: With the aid of 3D printing technology, designers can create models that are accurate and meet the exact specifications of the project. Customised designs, which have interestingly complex shapes, can be created via 3D construction printing, as 3D printers can achieve shapes that might not be readily achieved by conventional construction. Customised components and designs that enhance functionality and aesthetics be added to the building model. 

• Reduced time and cost: Because changes to the building model can be viewed and made upfront before printing, 3D printing in the long run is less expensive. Labour costs are also highly reduced and a building which might take months or weeks to create using conventional building methods is constructed in far lesser time than that. 

• Collaboration: Building Information Modelling allows for the efficient participation of all project stakeholders to modify designs, trade information, identify and resolve all potential issues. The structure is made to exact demands of the stated requirements. 

• Reduced risk of onsite injuries and fatalities due to a smaller labour force and the high automation of the process. 

• Less waste and greater sustainability: Because printed materials require only as much as is needed to construct the buildings, there is a reduced need for environmental resources and less wastage of resources excavated. 

Challenges Of BIM & 3D Printing Integration

• Expensive: Neither 3D printers nor BIM software is cheap. Learning can also be costly. 

• Lack of skilled pool: As it stands, the need for human intervention in the operation of both BIM and 3D printing software is ever present. Due to how uncommon the technology is, it is hard to find ready, cost-effective personnel who can manage and utilize each technology well enough. And when they're available, they're in high demand and expensive to hire. 

• Recognition: The field of BIM and 3D Construction printing needs to be better recognised by investors, manufacturers, researchers, constructors, designers and other industry participants alike for more exploration, research and funding into more specific areas of 3d construction printing such as green printing with waste component material, evaluating various forms of resistance and forming new BIM applications. 

• Due to how new the field is, the standards for this field have not been actualized yet. 

• With the advent of this technology, a lot of manual labourers in the construction industry are on the line to lose their jobs, which can lead to increased rate of unemployment and a hit to a nation's economy. 

3D Printing and BIM integration is a new field and is not popular for commonplace use. In fact, it is hard to imagine that 3D printing and BIM would replace traditional construction methods in the next few years. However, the technology is currently in use in developed countries for the creation of public infrastructure such as bridges in China. Its use is a net positive and brings great convenience at any time. Coupled with its other advantages, this technology is on the way to being the foundation for the building of the future.