A Path towards SDGs: Investigation of the Challenges in Adopting 3D Concrete Printing in India

Abstract

In recent years, three dimensional concrete printing (3DCP) has gained traction as a promising technology to mitigate the carbon footprint associated with construction industry. However, despite its environmental benefits, studies frequently overlook its impact on social sustainability and its overall influence on project success. This research investigates how strategic decisions by firms shape the tradeoffs between economic, environmental, and social sustainability in the context of 3DCP adoption. Through interviews with 20 Indian industry leaders, it was found that companies primarily invest in 3DCP for automation and skilled workforce development, rather than solely for environmental reasons. The lack of incentives for sustainable practices in government procurement regulations emerges as a significant barrier to the widespread adoption of 3DCP. Our study identifies five key strategies firms employ to promote sustainability through 3DCP and proposes actionable measures for government intervention to stimulate its advancement. Addressing these issues is crucial for realizing the full societal and environmental benefits of 3DCP technology.

1. Introduction

The building sector is a pivotal driver of global economic growth and energy consumption but is also a significant contributor to greenhouse gas emissions [1,2]. Globally, the construction industry accounts for 39% of the CO₂ emissions and uses 36% of the energy. Concrete, a cornerstone material in the construction industry, is particularly noteworthy due to its extensive use and environmental impact [3]. Concrete’s advantages include low cost, excellent fire resistance, and high compressive strength, which make it a preferred material in construction. However, its production is a primary environmental concern: cement alone contributes approximately 6% of global CO₂ emissions, and about 9% of all industrial water withdrawals are used in concrete production [4].

Despite its widespread application and benefits, the environmental footprint of concrete continues to worsen as urbanization and construction activities expand. Innovations like 3D concrete printing (3DCP) is being explored to address these challenges. Proponents of 3DCP argue that it can enhance sustainability by reducing material usage, minimizing waste, improving productivity, and mitigating the skilled labor shortage in the construction industry [5,6]. Although case studies and lifecycle assessments have quantified the economic and environmental benefits of 3DCP, they have often neglected the impact on social sustainability [7,8,9].

Previous research in 3DCP has focused on the technological advancements and potential benefits of 3DCP in the construction industry. An early study explored the potential for 3DCP to revolutionize construction by reducing material waste, labor costs, and construction time, thus offering significant environmental and economic advantages [1]. Examining the technical aspects of 3DCP highlights its ability to produce complex geometries and customized structures, which are difficult to achieve with traditional construction methods [2].

However, the social sustainability implications of 3DCP have received less attention. The environmental benefits of 3DCP, such as reduced carbon emissions and resource efficiency, are studied, but the social aspects, such as job displacement or the impact on local communities, are not deeply investigated [3]. More recent studies have explored the broader implications of 3DCP adoption, including economic and environmental factors, but again, social sustainability remains underexplored [4,5,6].

Moreover, studies have emphasized the role of governmental policies and institutional frameworks in promoting sustainable construction practices [5,6]. They argue that while 3DCP has the potential to contribute significantly to sustainability, the lack of comprehensive policies and standards hinders its widespread adoption [5]. Analyzing the regulatory challenges that 3DCP faces and recommending that sustainability criteria be incorporated into government tenders encourages the adoption of innovative technologies [6].

Moreover, previous analyses have not sufficiently addressed how managerial decisions affect the adoption of 3DCP and its implications for social sustainability. The institutional framework, which includes government commissioning large construction projects, is crucial in influencing companies’ sustainability outcomes [10,11,12]. To fill this gap, this study aims to investigate how management decisions regarding the application of 3D concrete printing (3DCP) affect the balance between environmental, economic, and social sustainability. The specific objectives are:

(1)

To examine how management decisions regarding 3DCP application impact sustainability across environmental, economic, and social dimensions.

(2)

To explore how current institutional conditions, such as government commissioning and tendering processes, influence management incentives to invest in 3DCP.

(3)

To identify key challenges in implementing 3DCP and propose policy changes that could facilitate greater adoption of this technology, enhancing overall sustainability.

The study uses a qualitative approach involving 20 interviews with 3DCP pioneers in India to analyze data across three dimensions: people, planet, and profit. The findings reveal that government tenders often lack sufficient sustainability criteria to promote widespread 3DCP adoption, highlighting the need to incorporate social sustainability considerations into implementing new technologies. The study’s significance lies in its focus on the intersection of management decisions, institutional frameworks, and 3DCP technology adoption. It addresses gaps in existing research by emphasizing social sustainability and the influence of institutional conditions, offering practical recommendations for policymakers and industry leaders to promote a more balanced approach to sustainability in the construction industry.

2. Background

2.1. Challenges and Promises of 3DCP in Construction

Various technologies are used to construct items by layering concrete until the final geometry is achieved. As with 3D printers that print metals or polymers, 3DCP machines work similarly [13,14,15]. In contrast to conventional printing methods, 3DCP allows structures, such as walls and even entire floors, to be printed in much larger sizes than those obtained from traditional printing methods. The larger the printed component, the more challenging it is to implement effective quality control, as minute faults are more likely to arise during printing.

3DCP technology most appeals to the construction industry because it allows complex geometric shapes to be produced using no formwork. A formwork project can cost over 10% of the total project cost, depending on the location and the type. As formwork can only be reused a limited number of times, it is typically made from wood and is a significant source of waste [16,17]. In conjunction with 3DCP, the printing procedure can be set up so that the least amount of material is used. Additionally, 3DCP reduces the environmental impact of concrete manufacturing and construction operations. Architects can also experiment with innovative building shapes using 3DCP to improve energy efficiency or airflow, thereby minimizing the environmental impact.

In addition to material savings, 3DCP is expected to generate financial benefits as well. The lack of technological sophistication and high demand for manual labor have contributed to a stagnation in construction productivity in recent years [18,19]. Construction in western countries is also experiencing a labor shortage. Employees from less developed countries may temporarily fill the vacancy, but there are more chances they will face social and professional difficulties. Human trafficking and forced labor are the most common ways criminal networks use undocumented and illegal workers.

Governments and businesses have suggested increasing prefabrication and off-site construction and digitizing the entire supply chain of construction activities to boost productivity. The construction process could be automated to eliminate structural defects and consistency issues with manual labor. Construction project planning is made more difficult by rework expenses related to these flaws, which could comprise 5–15% of the total budget [20,21,22]. Moreover, 3DCP equipment may theoretically continue working while manual building activities cease at night or during difficult weather conditions [22,23].

Even though 3DCP has the potential to contribute to sustainability significantly, it also has some drawbacks. One of the significant limitations of 3DCP is that it offers constructors few material options [24]. For instance, alternative binders like geopolymers, fly ash, and limestone are being incorporated into 3DCP to enhance the sustainability of 3D-printed concrete. Their rheological properties are different from traditional mortars. 3DCP materials must be produced, distributed, and recycled sustainably [25,26,27,28].

Furthermore, printed components are far less mechanically strong than cast concrete and susceptible to even the smallest manufacturing process modifications. This makes 3DCP not quite relevant. To build strong quality control and lower manufacturing variability, pioneers should extensively invest in R&D and go through protracted trial-and-error. To reap the benefits of 3DCP and save on materials, designers will also need retraining and time [29]. New technical standards and long-term durability tests for 3DCP materials will need to be developed.

The sustainability of 3DCP has been studied, but these studies focus on its benefits rather than its limitations. Studies that examine its limitations concentrate more on technical aspects than sustainability [30,31]. Usually measuring environmental and economic effects, 3DCP’s lifecycle assessment ignores elements of social sustainability and is limited to single case studies without accounting for regulatory influences [32,33]. A technology’s sustainability benefits, as well as its business model sustainability and the context in which it is adopted, can all influence how a technology is adopted, thus affecting the extent of its sustainability benefits. Although these interactions are crucial for assessing sustainability, the literature does not explain how 3DCP interacts with the triple bottom line [34,35]. Studies enhance the literature by incorporating social sustainability into evaluating 3DCP’s overall sustainability. It also examines how managerial and design decisions affect the trade-offs in environmental, social, and economic sustainability [36,37,38,39].

Certain features of the building sector hinder the application of 3DCP: the lack of specialized training programs and the unattractiveness of the construction sector as a career choice for young people; low levels of R&D spending; and a lack of skilled labor-led managers to adopt new technologies cautiously with low and unstable profit margins [37,38,39,40,41]. As a result, construction R&D focuses on incremental innovations, and market forces often drive sustainability. To help businesses overcome the sensitivity to risk that the industry has, governments have created laws and policies that provide incentives for companies to increase their sustainability to help them improve their efficiency [42,43].

3D concrete printing (3DCP) faces challenges such as rigid procurement rules, high initial costs, and the need for established quality standards, alongside potential resistance from traditional industry stakeholders and a shortage of skilled professionals. However, it also promises significant benefits, including innovation, increased efficiency, material savings, and reduced construction waste [44]. Governments can drive adoption by using public procurement to set technology mandates and waste management requirements, fostering long-term cost savings, job creation, and enhanced sustainability. By developing new standards and regulations, public procurement can effectively support the integration of 3DCP into mainstream construction practices [45]. Standardized indicators usually quantify the highest permitted degree of environmental harm caused by a project. Such performance-based indicators have the advantage that businesses can choose the solution that best fits their environment to meet the required threshold instead of being forced to employ a specific technology [46]. Regulations may have a technology-forcing effect if they cannot be met with current technology, causing businesses to develop new technologies [47].

Technical requirements and architectural codes are frequently tied to procurement regulations. To promote innovation throughout the supply chain, the government may adopt more stringent technical criteria [48,49,50]. How well new technologies follow established standards has dramatically affected their acceptance in the building sector. While standardization has substantially increased construction safety and homogenized procedures across enterprises, an overreliance on standards risks preventing the commercialization of technology advancements compatible with those standards [51,52]. With the advent of 3DCP, its design flexibility may clash with current standards favoring prefabricated assemblies with specific shapes where manufacturing quality can be more carefully monitored. The technology of 3D printing has also been under dispute with technical standards, resulting in a conflict between the two technologies [53,54].

A firm’s institutional framework will likely affect its decision to use 3DCP and, therefore, whether sustainability benefits can be realized. This institutional setting may have significant regional variation. The impact of the institutional context on the sustainability of 3DCP has not been considered in previous analyses [55,56,57,58,59]. Our paper contributes to the literature by offering insights into how managers in India perceive institutional incentives for adopting 3D concrete printing (3DCP). We anticipate that our findings will also be relevant to other countries in the Indian subcontinent, as they face similar challenges related to sustainability goals and construction standards, despite varying regulatory frameworks.

2.2. Research Gap

In the Indian context, while 3D concrete printing (3DCP) presents significant potential for enhancing construction sustainability, there remains a notable research gap. Existing studies often focus primarily on the environmental and economic benefits of 3DCP, with limited exploration of its social sustainability aspects and the influence of institutional frameworks on technology adoption. Specifically, there is insufficient data and analysis of how managerial decisions and government policies in India impact the integration of 3DCP and its effectiveness in achieving sustainability goals. The lack of specialized training programs, high initial costs, and rigid procurement rules further complicate its adoption. Moreover, the regional variations in regulatory frameworks and institutional incentives have not been thoroughly examined. This gap underscores the need for research investigating how these factors affect the implementation of 3DCP in India, including its impact on social sustainability and the broader implications for construction practices across the Indian subcontinent.

3. Methodology

This study comprehensively addresses each step of the research process, from the initial stages of research design and data collection to data analysis and the interpretation of findings, as illustrated in Figure 1.

3.1. Research Approach

This study utilizes a qualitative research approach to understand how management decisions and institutional conditions impact the adoption of 3D concrete printing (3DCP) in the construction industry, particularly concerning sustainability outcomes. A qualitative approach is appropriate for exploring complex, context-dependent phenomena that require rich, detailed insights [13]. To collect data, this study employed open-ended interview questions, which allowed participants to freely express their views and experiences regarding the adoption of 3DCP. These questions were designed to explore the three dimensions of sustainability—people, planet, and profit—and how they intersect with management and policy decisions. Preparing the interview questions involved a thorough literature review and consultations with subject matter experts to ensure that the questions were relevant and capable of eliciting comprehensive responses [32]. The selection of experts for the interviews followed a purposeful sampling strategy, focusing on individuals with extensive experience and expertise in 3DCP. Criteria for selection included their involvement in pioneering 3DCP projects, their role in decision-making processes related to technology adoption, and their understanding of the sustainability implications of 3DCP. This approach ensured that the insights gathered were informed by knowledgeable and experienced professionals, contributing to the study’s credibility and depth [33].

3.2. Data Collection

The data collection for this study involved a comprehensive qualitative approach, utilizing semi-structured interviews to explore the sustainability trade-offs and institutional challenges associated with the adoption of 3D concrete printing (3DCP). The interviews were conducted with a diverse group of 20 experts [60,61], including managers, structural designers, innovation managers, and sustainability consultants, and all had significant experience with 3DCP and its application in the construction industry (see Table 1). The interview process was designed to ensure a broad representation of perspectives from various stakeholders involved in 3DCP adoption. Interviews were conducted in English and local languages, including Kannada, Tamil, Telugu, and Hindi, to accommodate the participants’ preferences and ensure clear communication. Each interview lasted between 30 and 90 min, allowing for an in-depth exploration of the topics.

The interviews were structured into four main sections. The first section focused on understanding the characteristics of 3DCP and the challenges associated with its implementation. Subsequent sections explored how the adoption of 3DCP influenced the triple bottom line dimensions—people, planet, and profit—alongside the technical and financial hurdles of bringing the technology from lab to market. The final round of interviews was designed to identify sustainability trade-offs related to 3DCP and to compare it with other technologies available to businesses. A snowball sampling technique was employed, where initial interviewees recommended other potential participants, ensuring the sample was comprehensive and relevant to the study’s objectives. The iterative coding process involved three phases of hand-coding, focusing on technological sustainability features and their impact on the triple bottom line. The authors reviewed and refined the coding results collaboratively, ensuring consistency and reducing bias. This methodical approach provided a robust framework for analyzing the data and deriving insights into the sustainability implications of 3DCP adoption.

3.3. Data Analysis

The data analysis in this study was conducted through a rigorous and systematic process, following a qualitative approach to uncover patterns and insights related to the adoption of 3D concrete printing (3DCP) in the construction industry. The analysis focused on understanding the sustainability trade-offs and institutional influences on 3DCP implementation. Initially, the interview data were transcribed and subjected to a thematic analysis involving identifying, analyzing, and reporting patterns within the data [41]. The first phase of the analysis involved coding the interview transcripts line by line and categorizing responses based on key themes related to technological sustainability features, social sustainability considerations, and economic impacts. These themes were identified based on the literature and the data, ensuring that the analysis was grounded in the participants’ experiences and the study’s theoretical framework [44].

The coding process was carried out in three stages. In the first stage, technological sustainability features were coded, emphasizing how these features affected the triple bottom line—people, planet, and profit. The codes were then mapped against existing technical literature on 3DCP to assess whether the identified features positively or negatively impacted sustainability outcomes [47,48,49]. The second stage involved linking these codes to the strategic decisions made by organizations regarding 3DCP adoption and identifying trade-offs between sustainability and other operational priorities. The final stage of the coding process involved comparing the findings across different sectors and organizations, revealing commonalities and differences in how 3DCP is perceived and implemented. This comparative analysis highlighted the varied challenges and opportunities faced by different stakeholders in adopting 3DCP and the role of institutional frameworks in shaping these outcomes [50,51].

Throughout the analysis, the data were first independently coded, and then an additional perspective ensured the reliability and validity of the findings (see

Table 2. Trade-off in sustainability over three-dimensional CP acceptance parameters. Positive impacts as (+) and negative effects as (−) [62].

3DCP Trait	Effects on Earth	Impact on Individuals	Effect on Profit
Reduction in material use	+ Production of concrete and transportation help to lessen environmental effects. + Formwork is not needed, which is limited in reuse. − Still, concrete is a big and difficult substance. − There is limited material availability for 3DCP, hence longer distance travel could be necessary.	− Formwork not needed.	+ Potential cost and savings in formwork. − 3DCP materials are more expensive than traditional concrete. − Costlier alternatives to concrete.
Geometry freedom for complex designs	+ A holistic design approach can improve energy efficiency. − Holistic design could be less modular and contradict circularity.	+ The designs allow one to more readily fit the requirements of particular users. + Promotes high-skilled employment.	− Since integrated designs are difficult to evaluate, 3DCP’s cost-competitiveness cannot be readily matched with conventional designs.
Automation in 3DCP	+ A higher level of quality control results in less waste and fewer errors.	+ Automation will be the only choice should future construction personnel be lacking. − With 3DCP, concrete pouring calls for less work.	+ Significant savings connected to expenses related to failures. Low variability helps project managers to lessen their uncertainty. High equipment, R&D, and quality control expenses.

). There was a high level of agreement between the co-coders [52,53,54,55]. The iterative nature of the coding process, coupled with the triangulation of data from multiple sources, ensured that the analysis was thorough and reflective of the complexities involved in 3DCP adoption. The findings from this analysis contribute to the academic understanding of 3DCP’s sustainability implications and offer practical insights for policymakers and industry leaders.

Table 1. A chronological list of the interviewees.

Expert	Qualification	Experience	Area of Expertise	Interview Duration (mins)
Expert 1	Ph.D. in Structural Engineering	15 years	3D Concrete Printing, Structural Design	54
Expert 2	M.Sc. in Construction Management.	12 years	Project Management, Sustainable Construction	95
Expert 3	B.Eng. in Civil Engineering	20 years	Concrete Technology, Building Materials	74
Expert 4	M.Sc. in Environmental Engineering	10 years	Environmental Impact Assessment, Green Building Technologies	86
Expert 5	Ph.D. in Architecture	18 years	Innovative Building Design, 3D Printing Applications	46
Expert 6	B.Arch. in Architecture	14 years	Sustainable Design, Building Information Modeling	46
Expert 7	M.Sc. in Construction Technology	8 years	Construction Innovation, 3DCP Implementation	76
Expert 8	Ph.D. in Mechanical Engineering	22 years	Robotics in Construction, Automation Technologies	46
Expert 9	M.Sc. in Structural Engineering	16 years	Structural Analysis, Material Science	44
Expert 10	B.Sc. in Civil Engineering	13 years	Infrastructure Projects, Concrete Durability	46
Expert 11	M.Sc. in Environmental Design	11 years	Environmental Sustainability, Circular Economy	45
Expert 12	Ph.D. in Building Science	17 years	Building Physics, Thermal Efficiency	60
Expert 13	B.Eng. in Construction Engineering	15 years	Construction Technology, Project Management	58
Expert 14	M.Sc. in Architectural Engineering	9 years	Sustainable Architecture, 3D Printing	49
Expert 15	Ph.D. in Civil Engineering	19 years	Structural Integrity, Advanced Construction Materials	33
Expert 16	M.Sc. in Sustainability	12 years	Sustainable Building Practices, Environmental Policy	59
Expert 17	B.Eng. in Mechanical Engineering	20 years	Construction Robotics, Automation Systems	71
Expert 18	M.Sc. in Project Management	14 years	Construction Projects, Resource Management	43
Expert 19	Ph.D. in Environmental Science	16 years	Eco-friendly Materials, Life Cycle Assessment	54
Expert 20	M.Sc. in Urban Planning	13 years	Urban Development, Sustainable Design	87

Table 1. A chronological list of the interviewees.

Expert	Qualification	Experience	Area of Expertise	Interview Duration (mins)
Expert 1	Ph.D. in Structural Engineering	15 years	3D Concrete Printing, Structural Design	54
Expert 2	M.Sc. in Construction Management.	12 years	Project Management, Sustainable Construction	95
Expert 3	B.Eng. in Civil Engineering	20 years	Concrete Technology, Building Materials	74
Expert 4	M.Sc. in Environmental Engineering	10 years	Environmental Impact Assessment, Green Building Technologies	86
Expert 5	Ph.D. in Architecture	18 years	Innovative Building Design, 3D Printing Applications	46
Expert 6	B.Arch. in Architecture	14 years	Sustainable Design, Building Information Modeling	46
Expert 7	M.Sc. in Construction Technology	8 years	Construction Innovation, 3DCP Implementation	76
Expert 8	Ph.D. in Mechanical Engineering	22 years	Robotics in Construction, Automation Technologies	46
Expert 9	M.Sc. in Structural Engineering	16 years	Structural Analysis, Material Science	44
Expert 10	B.Sc. in Civil Engineering	13 years	Infrastructure Projects, Concrete Durability	46
Expert 11	M.Sc. in Environmental Design	11 years	Environmental Sustainability, Circular Economy	45
Expert 12	Ph.D. in Building Science	17 years	Building Physics, Thermal Efficiency	60
Expert 13	B.Eng. in Construction Engineering	15 years	Construction Technology, Project Management	58
Expert 14	M.Sc. in Architectural Engineering	9 years	Sustainable Architecture, 3D Printing	49
Expert 15	Ph.D. in Civil Engineering	19 years	Structural Integrity, Advanced Construction Materials	33
Expert 16	M.Sc. in Sustainability	12 years	Sustainable Building Practices, Environmental Policy	59
Expert 17	B.Eng. in Mechanical Engineering	20 years	Construction Robotics, Automation Systems	71
Expert 18	M.Sc. in Project Management	14 years	Construction Projects, Resource Management	43
Expert 19	Ph.D. in Environmental Science	16 years	Eco-friendly Materials, Life Cycle Assessment	54
Expert 20	M.Sc. in Urban Planning	13 years	Urban Development, Sustainable Design	87

4. Findings

4.1. Environmental Sustainability: Good Promise, but There Are Questions Regarding Complete Circularity

The careful balance between the advantages they can get and the costs they pay determines construction managers’ application of environmentally friendly technologies. Usually, major actors in big infrastructure projects are governments. Therefore, the government tendering process has great impact (“Decision-making is often at the project or tender level, so the tender manager or project manager must convince them of the added value.”). Usually, the candidate proposing the most economically advantageous tender (MEAT) gets the project. Tenders could contain environmental factors like predicted effects on acidification, water eutrophication, and climate change. MEAT requirements are decided upon in India project by project. It is necessary to evaluate applications twice. Initial evaluations are conducted by independent experts who are not aware of the final price of the tender.

The procurer uses these qualitative factors to calculate the price based on evaluating these factors. A MEAT price (ECI) is calculated based on environmental cost indications associated with each material in the project. Shadow costs per kilogram of material consumed are computed using an ECI that accounts for a material’s production process, transportation distance, and disposal. ECI materials must be purchased from a qualified source or certified by the contractor to determine the total cost. 3DCP materials do not contain these certificates. A company is not encouraged to undergo the certification process, as the estimated amount of 3DCP would represent only a tiny portion of the total material used in the project. “For concrete, we first have to get all kinds of certificates, and it takes much time, so you cannot easily implement it … it does not always have to be cheaper, it can also have a better environmental score … [but] we are not there yet”. In addition to its rapidly expanding composition, 3DCP blends are exclusive to a select number of material sources that consider these blends a significant source of competitive advantage, making certification even more challenging.

ECI ratings and MEAT allowances must reflect values that promote innovation and technological advancement to be effective. Still, our interviewees felt that “the [ECI] values now set as the maximum are so high that, in practice, you are almost always below these numbers”. Consequently, there is no actual urgency to lower environmental effects. Some interviewees identified a 3DCP opportunity in tenders where MEAT was not the primary criterion. They underlined “a tender in which 50% of your plan is rated on image/quality (aesthetics), 35% on flora/fauna, environmental nuisance, road safety, and 15% on price, ranging from 0 to 100”. To win, then, you must make investments in image and quality. An applicant making such a bid should be advised to use 3DCP to create complex geometries that are more sensitive to local ecosystems and restrict the visual impact instead of using it to reduce the ECI score.

Though they are now lacking, ECI scores should become tighter going forward. The building sector claims that if the E.U. is to reach climate neutrality by then, all building components must be circular by 2025. All significant Bengaluru construction firms have made their strategic plans for circular buildings public to comply with future regulations.

There are tensions between opportunities and challenges with circular concrete, according to 3DCP. Due to the high amounts of trash and the requirement for formwork, “the demand for material is more than what becomes available. Secondary [recycling] is a significant problem in constructing concrete structures”. By radically reducing material usage, 3DCP eliminates formwork. Reducing material use will not help if it cannot be used to print 3D again. One way to solve the recycling issue is creating new material combinations with less or no cement and simpler treatment at the end of their lifetime. The results of such mixes are still relatively unknown despite the efforts of academic and industrial studies. Many interviewees mentioned they were considering replacing concrete structures with alternative materials like wood or composites. While acknowledging that “we must continue to use [concrete] because, for certain applications, there is no fully-fledged alternative”, one manager we spoke with said: “it is better to invest time and energy in these kinds of concepts than in a technique/material that by definition can never be sustainable”. Today, concrete is admired for its affordability and durability, and substituting concrete is challenging. “In civil concrete construction, production is fully functional, and all concrete is there because of its strength”.

Furthermore, while 3D concrete printing (3DCP) offers significant design freedom, it is important to consider how this potential aligns with the actual needs of the construction industry. 3DCP also allows for the creation of intricate and aesthetic shapes that would be difficult or impossible to achieve with traditional construction methods. This opens up new possibilities for architectural design and expression [63]. A notable advantage is the ability to create modular constructions that can be easily deconstructed and replaced. However, this modularity contrasts with the benefits of building entire structures in one go with minimal assembly. The technology can better address practical needs by integrating 3DCP’s design flexibility with industry requirements for modularity and efficiency while enhancing overall construction practices. Modular construction offers significant productivity benefits by reducing construction time and increasing efficiency. With prefabricated modules that can be easily assembled, construction projects can be completed in a fraction of the time compared to traditional construction methods. It saves time and money and allows for faster occupancy and quicker return on investment. Building a demountable is also essential to your design, as you must consider how the connection between your design and the monolith will differ. Modular designs become more circular as everything is baked together in 3D printing. By contrast, consolidated designs offer higher performance, reduce weight, and extend component life. Modular designs are easily circularized. To protect the integrity, additional material is needed whenever two components are joined.

The technology appears to represent a significant advancement in reducing the building sector’s environmental impact over the current situation. Although 3DCP might eventually satisfy circularity requirements, there are several unanswered questions. In some cases, alternative materials can be used instead of concrete, but it is unclear whether concrete can be replaced entirely.

4.2. Social Sustainability: Lower Reliance on Seasonal Labor and Higher Levels of Satisfaction among Building Occupants

For its operations today, the Bengaluru building sector mostly relies on seasonal foreign labor. “If you look at civil concrete construction, such as iron braids, workers are mostly UP and Bihar, and you hardly see any Bengaluru”. Importing labor is less expensive economically than hiring workers from India. Managers claim that over time, this condition is not sustainable. Labor prices will probably increase as the economies of the nations where seasonal workers come from project growth in the next years.

Furthermore, the labor shortage is anticipated to worsen over the next several decades. Automation is driven primarily by these two trends: “In 20, 30 to 40 years, you will have few people who still understand the profession, so you will have to switch production … you can see that the number of people learning a trade like carpenter is decreasing, there are only a few”. From this vantage point, technology would not drive workers out of the market; instead, a lack of labor would drive technology into industry. 3DCP would aid in removing the social issues brought on by seasonal workers’ unstable employment, their challenges assimilating into new societies, and the possibility of immigrant labor exploitation by diminishing the demand for seasonal employees.

By replacing conventional concrete pouring duties with its components, 3DCP will impact various jobs, depending on its use. Whether 3DCP should be done on-site or off-site—prefabricated in a factory—is a significant question with much ambiguity. If prefabricated modular components were constructed by a team of workers at the building site, 3DCP would become merely another off-site tool. Labor consequences would be negligible and only affect some professions, such carpenters in countries like India, where a considerable amount of the construction is prefabricated (since wooden formworks for pouring concrete would no longer be needed). The impact might be more important in other countries where prefabrication is rather less widespread. Using 3DCP on-site might theoretically allow a huge robot to print the whole building structure. In such a case, a bigger workforce would be affected since labor would only be needed for operation management and the building and calibration of robotic equipment. Human effort would still be needed for installation of plumbing and electrical equipment that is not yet automated.

Moreover, 3DCP should increase worker safety (“Creating formwork is relatively dangerous; more than one carpenter lost a finger; sawing or cutting wood”). Furthermore, even in cases of an accident involving 3DCP technology, the employee’s injuries will be far less severe (“A printer may break, but no one will be injured or killed”). As with current prefabrication methods, 3DCP has risks similar to those of factory workers since it can be used off-site. Using 3DCP technology for construction can significantly improve worker safety by reducing the risk of accidents and injuries. With 3DCP, carpenters do not need to handle dangerous tools and materials, such as in cutting wood or sawing, which are often associated with accidents. Furthermore, 3DCP is automated, drastically reducing the possibility of equipment-related mishaps and guaranteeing staff safety. Off-site buildings offer fewer work-at-height chores and less total control over the manufacturing environment than on-site buildings.

As is sometimes observed on building sites, “around 150 individuals stroll about during busy times. A lot of people are still on site. I wonder whether 3DCP printing could be useful there.” 3DCP could stop mishaps by easing worker interaction and congestion.

Developing training plans is crucial if one is to enjoy these advantages. One of the main obstacles to extensive acceptance of 3DCP (“If you want to do it [3DCP] yourself, you also have to train your people”). Although there are only a few professional training courses, universities have begun instructing their students in 3DCP construction. Apart from the staff, 3DCP could improve the usability of a construction for its final users. Raising the thermal efficiency of a building has great possibilities. While concrete provides inadequate insulation, 3DCP allows the building of hollow constructions that may be filled with better insulators much more easily.

Additionally, depending on their location and intended usage, buildings might be constructed to maximize aspects like sunlight, ventilation, or acoustics. A comprehensive approach to building design is necessary to “add this integration without adding the extra costs” 3DCP promises. In theory, achieving this full integration would enhance a building’s occupants’ comfort and quality of life while lowering energy usage and, consequently, the energy bill.

However, according to two people we spoke with, moisture control is a significant barrier to using 3DCP structures. Concrete does not “breathe”, unlike other wall surface materials like gypsum. Maintaining consistent moisture throughout the day is crucial in places with high humidity, and this can be a serious problem to deal with. During freezing weather, where water can freeze, no water drops must enter the concrete structure. These issues are resolved using specialized surface treatments. Another option is to build structural features into the walls, like rain screens, at the building time. The building’s location will inevitably affect the chosen solution because it must also adhere to local regulations.

4.3. Sustainability Economic: High R&D Expenditures Due to the Immaturity of Technologies

The current state of 3DCP, while innovative, presents challenges compared to traditional concrete pouring methods, particularly in cost and long-term performance. One interviewee noted, “All these companies advertise that you can print a house in 24 or 48 h. However, one key drawback of 3DCP is the potential compromise on structural integrity”. While it may be possible to print a house quickly, concerns about the long-term durability and strength of the printed structure remain significant. Rigorous research and testing are essential to ensure that 3DCP can meet the same safety and sustainability standards as traditional methods.

Moreover, 3DCP employs fundamentally different design principles, requires operators with specialized skills, and involves distinct quality control and maintenance protocols. While the initial costs of 3DCP structures may be higher, their advantages in comfort, thermal efficiency, and potential energy savings can offset these expenses over time. However, comprehensive cost–benefit analyses are complex and require advanced tools. Furthermore, the long-term performance and maintenance of 3DCP structures are critical factors in assessing their overall sustainability. Construction firms may hesitate to invest heavily in this still-maturing technology without additional institutional support, especially when direct cost reductions are not immediately evident.

According to interviewees, two main factors contribute most to the cost of using 3DCP, and these factors could be reduced if they were considered: materials and quality control. There is a challenge in that the average cost of a large construction varies from a low cost per kilogram to a high cost per ton. In general, a house costs one euro a kilogram. 3DCP materials are much more expensive than traditional concrete mixtures because there is not enough demand to scale up production and achieve economies of scale, and there are not many suppliers. Without competition, material suppliers do not have to lower their prices. Furthermore, because there are only a few suppliers, materials must be transported over longer distances, increasing transportation costs and environmental impact.

A significant portion of the final cost of 3DCP structures is devoted to quality control, as there are no standardized procedures for designing 3DCP structures. “What Eurocodes has now is Design by Testing … we have to make a 1:1 prototype, test it, and based on that test, we can 3D print it and get it certified as safe … This process is costly because you have to make a bridge or house twice”. Once the final product has been built, non-destructive diagnostics testing is carried out. For instance, a bridge might be tested by putting the maximum load the bridge design allows on it and checking that the structure holds. As researchers produce digital twins to replicate the behavior of 3DCP structures, “the more testing you do, the more efficient your digital twin becomes as you feed it more data in the future, these digital twins will help to create building codes”. Testing costs should thus drop.

Further, there are concerns regarding the long-term behavior of materials. In some tenders, contractors must ensure that a bridge lasts 100 years. However, there is considerable uncertainty about whether 3DCP structures will fail in the future in unknown ways. “It will cause great anxiety; should we have a bad experience, the guidelines [construction codes] will once more be tightened. People want [innovation], but if at some point it gets project-specific and you discuss it at the project level, their overwhelming worry is the 100-year lifespan”. Tightening the building codes probably would make 3DCP less appealing.

3DCP presents two appealing benefits despite the economic challenges: better consistency and lower formwork costs. “Formwork costs almost a third of the total costs; cement and labor makes up the rest proportionate; that’s right, formwork accounts for about 50% of the material costs”. Although 3DCP materials may be more expensive, the time and money saved on constructing formwork and hiring labor to pour the concrete may offset the cost. The interviewee said the most interesting uses are “where people are in danger, where you print highly complex objects, somewhere in between, under the ground, or in tough places”.

There is unpredictability in 3DCP compared to manual labor, which is like any other automated process. “People can do things right today but wrong tomorrow; you are not in control and the 3D printer either prints something right or wrong”. Companies who can employ 3DCP to attain structural characteristics can save much money. The extra cost of 3DCP could be traded off in terms of the reduced chance of rebuilding a given component. Failure expenses are great, and the profit margin ranges from 2% to 3%. Our actions either reduce or convert earnings into losses. If we are talking about risk, it would be better to purchase one more costly prefabricated pile than three inferior piles, for which I will have to build two afterwards. Reducing the demand for rework will also help to lessen environmental effects.

4.4. Preserving Harmony between the Surroundings, People, and Business Interests

Our study especially illustrates the industry’s opinions on 3DCP possibilities and difficulties. Although 3DCP has the potential to increase construction sustainability significantly, early adopters will have to make some tradeoffs along the triple bottom line. We summarize our findings in Table 2, which emphasizes 3DCP’s tensions between people, planet, and profit. In Table 2, 3DCP proponents summarize its main benefits in horizontal rows. Each column represents the triple bottom line.

5. Discussion

5.1. Decisions That Affect the Sustainability of the 3DCP

Our research suggests that how a company uses 3DCP will significantly impact the sustainability benefits it offers. There is no established adoption plan due to the current level of technological uncertainty [56,57,58,59]. As a result, businesses seem to be approaching technology with caution. We examine five crucial options for construction organizations regarding 3DCP, together with their consequences for sustainability, to aid managers in their decision-making (see Table 1) [64,65,66,67]. Every company’s short- and long-term strategic goals will determine the optimal course of action; hence, these decisions are interrelated.

First, whether to invest in 3D printing technology and, if so, whether to employ concrete as a base material is fundamental to the second choice [68,69]. Using 3DCP could help to lower the environmental effect of building activities and enhance structural performance. Modern robotic equipment requires significant research and development investments to acquire the knowledge to design and construct sturdy structures [68,69,70]. Concrete may not be sustainable in the long run. 3DCP can simplify the process of designing safe concrete constructions since businesses are already familiar with the properties of concrete [71]. One of the downsides of concrete is that it is no longer recyclable or reusable. Although numerous research initiatives are underway to create more ecologically friendly material mixtures suitable for 3DCP, the details of the materials and the timing of their commercialization are unclear [72,73,74,75]. 3DCP may delay the shift to a circular economy; concrete must be discontinued as soon as possible, as some interviewees assert [76,77].

On the other hand, a 3DCP implementation can help companies become acquainted with digital infrastructures and material design ideas. Installed in Amsterdam in 2018, MX3D is a 12-m-long 3D-printed stainless-steel bridge [78,79,80,81,82]. Since concrete would have had detrimental environmental effects, this bridge benefited from 3D printing.

When a corporation uses 3DCP to design a product, three options govern the design process [83]. One of the decisions that needs to be made is creating integrated or modular structures [84]. Modular structures are considered more sustainable than integrated ones to reduce waste and boost circularity in some parts of the finished building that can be replaced without altering the entire structure [85,86]. However, it is essential to note that modular constructions require additional materials due to the stress concentration areas created by the connections between the different components [87]. The authors recommend that, to figure out whether a design should be modular or integrated, three factors should be taken into consideration: (1) the possibility of achieving light weight, (2) the capability of improving performance, and (3) the expected longevity of the system [88,89,90].

Additionally, businesses must decide whether to “produce or acquire” 3DCP components [91]. If a company lacks the expertise to make specific components or there is little technological opportunity, they will often outsource some of their production. On the other hand, companies typically vertically integrate component manufacture if the final product’s complexity is notable or if they consider it as a crucial expertise and competitive advantage [92,93]. Companies now contract with specialized suppliers to produce 3DCP components [94]. Businesses could find it beneficial to insource 3DCP activities, nevertheless, if technology develops to the point of replacing specialist building technologies as the standard [95,96]. General Electric acquired the 3D printing machinery manufacturers Arcam and Concept Las to perform metal 3D printing [97,98].

The final consideration for 3DCP adopters is whether it is preferable to make components locally or elsewhere [98]. On the one hand, off-site component production could enhance process control and part quality, two significant technological constraints in developing manufacturing technologies [99,100]. Still, off-site components must be transported from the manufacturer to the building site. The demand for transportation limits the biggest component size that can be produced [101,102]. On the other hand, building contractors may quickly erect larger structures without the trouble of transportation when components are produced on-site. Printing is also less reliable and possibly more prone to error on a construction site because of the constantly changing environmental conditions [103,104,105].

Location, outsourcing, and modularization considerations are all closely related [106]. Modular designs make a more adaptable supply chain possible, which may encourage supplier rivalry [107]. Outsourcing could be less expensive than making components internally if supplier competition lowers prices [108]. Modular design can be the most financially realistic choice when off-site manufacturing is desired, and quality control is a top priority [109]. In contrast, companies that wish to take advantage of the performance advantages of 3DCP, such as the reduction in manual assembly, may consider using on-site 3DCP for large, consolidated constructions [110,111,112,113]. Under such circumstances, 3DCP would become essential for their company operations, and companies would choose to internalize 3DCP responsibilities [114,115,116]. It is necessary to consider each organization’s characteristics and the anticipated technological advancement rate.

5.2. Policy Implications

A shortage of skilled labor and low tender requirements currently hinder the widespread adoption of 3D concrete printing (3DCP) technology. To address these barriers, targeted government intervention is needed in three key areas: experimentation and data sharing, workforce development, and establishing stringent tender requirements. The government can significantly influence the adoption of 3DCP by promoting regulation and standardization, garnering public support for funding pilot projects and forming public–private partnerships for data collection and analysis. Reducing the uncertainty around 3DCP’s structural behavior will aid industry acceptance; thus, public committees could facilitate this by standardizing and characterizing 3DCP mixtures to overcome suppliers’ reluctance to share data.

The skilled labor shortage, exacerbated by the introduction of 3DCP, underscores the need for robust training programs tailored to this technology. Expanding existing 3D printing training initiatives to include materials like metals and polymers can support this goal. However, given the significant differences between 3DCP and other 3D printing applications in mechanical properties and component sizes, specialized construction-oriented training programs are essential. Strengthening these socio-economic aspects will provide a more comprehensive understanding of the changes 3DCP may bring to the labor market and social structure.

6. Conclusions and Future Scope

Three-dimensional concrete printing (3DCP) presents significant potential in reducing construction’s carbon footprint; however, many challenges remain, particularly concerning the environmental impact of raw materials. Conducting a comprehensive environmental impact assessment of the raw materials used in the 3DCP process is essential to identify whether alternative material combinations could further reduce environmental impact. Additionally, a thorough study of how design decisions, such as the level of modularity and the thickness of 3DCP structures, influence both circularity and overall performance is necessary to realize this technology’s sustainability benefits fully.

Social sustainability can be significantly influenced by 3D concrete printing (3DCP) through its impact on the construction industry and the availability of low-skilled labor. While 3DCP can reduce reliance on seasonal labor, it may also affect employment opportunities for low-skilled workers. Construction automation could decrease the demand for these workers, leading to significant challenges for the industry and its workforce. To fully understand the implications of this technological change, further investigation is needed to analyze the full impact on the quantity and quality of construction jobs that could be affected by a higher level of automation.

3DCP’s cost-competitiveness, compared to other options, is currently unavailable to construction managers as a decision-making tool. Technoeconomic models should consider cost, quality, labor, and maintenance factors. It is difficult to predict the effects of technological inflation on costs due to rapid technological advancements and limited market strategies for 3DCP materials and equipment. Analyzing historical cost evolution in prefabricated construction or other industries can help forecast expenses better.