The integration of the suggested framework within BIM allows not only to  shift from the theoretical to the practical level but also to create a  well-framed and organized set of data of the facility during the whole life  cycle. To this end, the first step is the implementation of the LCA information  in BIM, enriching the set of information just embedded in the model and connecting  when possible the data with the relative physical objects. Note that for the  moment the LCA information in subject concern only quantitative information,  keeping out the environmental information since their values do not depend on  AEC practice and are mainly attributed to external database or EPD. The second  step is the clustering of LCA information in relation to the phase of the  design process, including a wider range of data with the advancement of the  process. The third step is the arrangement for each LCA information of the additional  linked data such as the actors responsible for the data insertion and the  source where data are gathered. This stage acquires a key role within AEC  practice since the sources used are expected to be even more specific and  detailed, in order to provide information gradually more accurate and reliable  in conjunction with the development of the design process. Moreover, also the  actors involved are expected to be various in relation to the phase of the  process, in order to empower designers, engineers, contractors and facility  managers to make responsible decisions and operations in their own expertise  area. These factors become crucial if the final goal is to orient and  streamline the AEC design process in line with environmental target and life  cycle perspective.
By joining LCA approach and BIM environment by means of the proposed  framework, BIM turn out to be not only as a shared platform of exchange among  the different practitioners and stakeholders and as a life cycle information  database of the facility, but also as a feasible supporting tool to reduce the  environmental impacts of the AEC value chain and so of the whole construction  sector. In fact, regardless the environmental data and the methodology employed  to develop a possible LCA study, if the project’s LCA quantitative information  are lowered in value with the progressive advancement of the design process,  necessarily also the relative impacts of the facility will decrease on the  environment. Moreover, in this way, since BIM is already widespread within AEC  practice (although at different levels), it would become a reliable basis for  decisions during the facility life cycle from the inception onward. If in the  next future the suggested framework will become an integral part of the AEC  practice, significant reverberations would be visible at the different scale. Firstly,  the adoption of Life Cycle Thinking in the built environment with the resulting  change of mind of all the actor engaged in the design process. Secondly, the  implementation of the LCA method as an effective decision supporting tool in  design process and therefore the enhancement of the following LCA studies with remarkable  improvements both for the completeness and the reliability of the information  considered. Thirdly, the activation in the construction sector of the type of  mechanisms able to start the process of improvement and optimization in line  with life cycle perspective and environmental targets, as demanded worldwide by  Sustainable Development Goals.
Furthermore, besides the benefits that such application entails for the  design process and, in general, for the environment, it should not neglect the  added value for owners and clients. Indeed, from early design to even the  decommissioning phase, all stakeholders contribute information to and extract  information from the shared model, providing a lifelong view of the facility.  In this way life cycle BIM allows a continuous built-up of know-how, enabling, on  one hand, a seamless flow of information across process phases and stakeholders  and, on the other, a life cycle database strategical also for owners and  clients to have full control of the facility and thus a more efficient asset management.
However, in this perspective, it is important to not underestimate the  following main barriers. First of all, the fact that the framework  implementation presumes the BIM equipment at least of all the AEC firms  involved. Nowadays the uptake and maturity of BIM vary considerably from  country to country and from company to company, according to their size and  position in the value chain. Indeed, for some big companies it is already part  of current practice and business, but most small companies have little or none  experience about it. The second barrier is the need of a “wide and open” BIM,  which integrates the entire value chain and it is characterized by full  interoperability of software and open access to it. While the technical challenges  are likely to be overcome in the next future, it might result more difficult to  change in an increasingly disruptive way the existing processes and to enhance  collaboration, including data sharing. Lastly, the fact that digital  technologies will realize their full potential only if they are widely adopted  and regulated by norms and standards. This task is crucial to create a fertile  environment for the digitalization of the construction sector and, in any given  country, it is demanded to the government, as regulator and incubator as well  as often a key project owner.
Since BIM and LCA are available methodologies and the construction  sector is just involved in the process of transformation and change management,  the need is to seize the opportunity, orient the process development in the  right direction and know how to exploit the most of it.

Deepening methodologies and tools in LCA and BIM environment

At this point, the framework has been disclosed and developed with the  aim to understand how to orient and streamline the design process in line with  environmental targets and life cycle perspective. After arguing it, before from  the theoretical/conceptual point of view and then from the practical/applicative  point of view, the focus turns back to the initial subject of the research: AEC  firms. The purpose is to try to indicatively verify the practicability and  feasibility of the suggested framework, analyzing the current practice in  relation to the main issues in question.
From the analysis of the questionnaire surveys available in literature, regardless  of the target audience, the perspective of AEC firms seems clear. BIM adoption  is on the rise essentially because fosters collaborations among many  disciplines and stakeholders typically regarded as individual building tasks, with  visible results in saving time and money as well as improved quality and more  efficient buildings. In addition, the utilization of BIM as a catalyst for  sustainable design and construction practice is growing within AEC sector.  Indeed, Green BIM turns out to be strategic for the following performance  analysis: building orientation, building massing, energy modeling, daylight analysis,  water harvesting, sustainable materials, HVAC design, green building  certification, cost estimating and so on. However, since most of these green  activities rely on external performance analyses software, despite the wide  range of tools today available, software-interoperability remains one of the  greatest challenges for the success of BIM and Green BIM in practice. Note that  interoperability concerns not only the technological level, as generally conceived,  but involves four broad layers of complex systems: technological, data, human  and institutional. The technological layer is the hardware and code that allow  the connection of different software and thus the exchange and share of data  through an explicit and agreed-upon interface. The data layer is the ability of  interconnected software to understand each other and process what is being  transmitted, representing a prerequisite for making the technological layer  useful and effective. The human layer is the ability of humans to understand  and act on the data that is exchanged and shared. The institutional layer is  the ability of societal systems to well engage and handle interoperability, for  instance from the legal point of view in relation to responsibility roles.
Regarding LCA, the questionnaire surveys available concerns specific  contexts but can probably be generalized to all the practice that use LCA. Interviews  indicate that the main drivers for doing LCA are building owners/clients,  followed by designers, codes and LEED requirements. Moreover, they emphasized  that building LCA is time-consuming and expensive, with huge difficulties in  finding and collecting data and with problems in the comparability and  transparency of LCA results. They outlined the need to find new efficient ways  of performing LCA in the early design stages through easy-to-use tools and  database, the need for a better understanding of the relative significance of  the different factors and building part and the need to refine and harmonize  the existing building LCA tools and databases.
Nowadays, copious LCA software are available on the market to encourage  LCA application within AEC practice and enable practitioners to make aware  choices in terms of environmental impacts. Given the complexity of the  construction sector and its close relationship with the surrounding context, buildings  LCA tools generally refer to national context, both for the  compliance with regulations and for the database embedded, even if some of them  take a wider perspective. Just to mention a few, LCA tools developed for  general purpose and spread worldwide are SimaPro and GaBi, while the ones  developed specifically for building sector are: Ecosoft in Austria, Elodie in  France, Legep in Germany, Ecoeffect in Sweden, Impact in United Kingdom, Lisa  in Australia, Athena in Canada, Bees in USA. Each tool possesses its own characteristics  which affect the spread of the methods in practice and the completeness of the  resulting LCA study. The main features to take into consideration are: the  context of reference, that is meaningful to understand the purpose and the  possible dissemination; the cost, that shows the level of accessibility and  diffusion of the tool; the degree of analysis, that allows, if provided, to  perform different level of analysis in relation to the phase of the project;  the database adopted, that strictly influence the accuracy of the study, based  for instance on their updating according to Environmental Product Declarations;  the output environmental indicators, that influence the results interpretation;  further potentialities, such as the inclusion of the technical systems, the  evaluation of cost and the interoperability with CAD and BIM tools \citep{ADV2016}. However, the problem  is that to offer accessible and comprehensible tools to a wider audience, they  tend to simply LCA methodology and the set of information required, providing  only in rare cases different level of detail. The result is that they are  generally used for finished projects, when all construction materials are  defined, and only in sporadic cases as supporting tools to compares  alternatives and orient decision-making process. To fill this gap and given the  potentialities of BIM, some producers work up on LCA software interoperable  with BIM tools, such as Tally and IES IMPACT Compliant Suite, employed at  international level, and Elodie, adopted in France.
Certainly, the implementation of LCA in BIM provides several advantages  for AEC practice, as shown below. The chance to achieve a holistic overview of  the project including environmental criteria starting from the early stages.  The accomplishment to enable better decision-making by providing feedback from  the beginning on the environmental impact of building design choice. The  solution to the redundant, manual and time-consuming tasks, typical for the standard  processing of LCA. The guidance to material and dimensioning decisions that  mostly determine the facility’s environmental impact. Lastly, a general optimization  of LCA processes and life cycle management. Nevertheless, most of the studies  available in literature perform LCA with the support of BIM but relying for the  assessment on external LCA software (for instance SimaPro, LCADesign,  Athena EcoCalculator and Athena Impact Estimator), recalling the problems of  data- and model-exchange. Indeed, actually BIM turns out to be useful basically  for: i) the automatic quantification of materials and components, profitable  for all material-based LCA information; ii) the development of energy  performance simulations, profitable for the use phase analysis; and iii) the  quickly comparisons between different design alternatives. Still a long way it  is required to make LCA implementation in BIM really effective for AEC practice  and decision-making process.
LCA method is not yet common in design and construction practice and,  when adopted, the environmental analysis performed by firms are not available  for all. For this reason, to understand how LCA studies are generally worked  out, the literature studies are the only reference point. Nonetheless,  it is important to underline that, in literature studies, LCA is performed  ex-post by researchers only for research purposes without affecting the project  decision-making process and so not representing properly the current state. Anyway,  the review of the LCA studies allows to verify the completeness and the quality  of the considered LCA information and, therefore, to understand how to improve  the data retrieval and the information flow management of future evaluations,  also concerning the framework previously proposed. Based  on selected studies, quantitative LCA information were identified for each life  cycle stage, pointing out the types and the quality of data considered,  starting from the most virtuous cases. The quality of data was established in  relation to the reference sources used to gather the information (e.g. high  level if personally monitored and gradually lower level if calculated from  technical project documentation or deduced by statistical and literature data).  Instead, the types of data refer to the information taken into account in the  inventory phase and, comparing them with the complete list of information  required to perform an LCA study, the data currently excluded were highlighted,  suggesting possible areas of improvement \citep{ADV2017}. From the analysis of literature LCA studies,  it emerges that in all studies some life cycle stages are omitted as well as  some of the required information. Moreover, depending on the cases, the process  of quantitative data collection occurs by means of the following sources,  explained in order of data appropriateness in relation to the peculiarity and  objectivity of the evaluation. Measurements, based on direct survey activities  carried out on-site. Questionnaires, based on interviews to suppliers,  contractors and/or entrepreneurs. Project documents, based on technical  drawings, reports and other supporting materials of the facility in question. Statistical  data, based on statistical analysis performed at municipal, regional, national  or international level. Hypothesis, based on personal assumptions without any  reference to reliefs and literature. Indeed, lack of data is still now  considered as key issue in the development of LCA evaluations.

Mapping environmental issues in AEC practice

The next phase in the works concerns the second type of interview that,  given the multitude of variables on the line in design practice, focused on  real case studies with a personal engagement in certain AEC firms in order to  map ex-post the design process of the specific projects, stressing  environmental issues and their role in decision-making (WP4 e WP5 – partnership  and analytic phases).
The prerequisite of this step is the involvement of punctual  partnerships with some worldwide AEC firms, establishing agreements to spent  few months of the PhD activity in their office and to encompass their practice  in the study. This phase is pivotal for the research project, representing from  the companies’ point of view an effort but at the same time an opportunity for  their workability. For this purpose, it is important to have the chance to  engage a representative number of firms, different in type and practice, to be  able to take a wider perspective as possible. The strategy adopted for the  selection endorses the AEC firms already in touch thanks to the questionnaire  survey. Moreover, to take advantage of the period abroad two foreign cities  (e.g. London and New York) were selected as strategic for building design,  given the concentration of firms and then ideally the possibility to analyze  simultaneously different practice. Since the feedbacks received were limited  and without concrete proposal, the boundary is now expanded to other AEC firms,  especially seeking the ones at the forefront of environmental issues or anyway  considered environmentally friendly. Two different ways are pointed out for the  selection: i) the identification of the projects certified by Green Building  Rating Systems, such as LEED, DGNB, BREEAM, to involve the companies  responsible for their design; ii) the dissemination of LCA tools in AEC  practice, to understand the users of the software solutions available on the  market, such as Ecosoft, Elodie, Legep and Impact. Specifically, the countries  in object turn out to be: Switzerland, Austria, France, Germany and United  Kingdom. The involvement of the partnerships aims to pinpoint the case studies  of the research project. Indeed, a case study is picked out from the portfolio  of each company selected, choosing a settled and possible built project  considered environmentally friendly and possibly equipped with and LCA study.  The decision to opt for concluded projects and not to ongoing decision-making  process is due to time restriction and to the intent of deepen a higher number  of projects, recreating thus ex post the design process instead of supervise it  when underway.
The identification of different case studies aims to understand how  deeply environmental issues are considered and faced by AEC practice, since at  first glance more or less every design firms claim to be environmental friendly  to take advantage for their business. To achieve this goal, the effort is to  map the design process of a growing number of projects, based on the  partnerships feedbacks received from the companies, trying to involve as much  as possible type of firms and ways of practice, and focusing on environmental  issues. Note that environmental issues are here conceived as the five core  environmentally aspects: material, energy, water, waste and carbon as well as  the interrelationships between the facilities and the surrounding environment.  Analyzing and mapping the design process, the focus of the research is to point  out all the resources invested by the companies to achieve environmental  targets and to understand how they influence the decision-making process. In  particular, three entities are taken into consideration: i) the team of humans,  including all the actors and experts involved in the design process; ii) the  set of tools and the assets, including all the physical items, computer and  software necessary to design; and iii) the collection of data, including all  the information required both by experts and tools to work and design.
Moreover, since there is no pre-determined relationship between the  resources of a firm and its capabilities, the mission is to figure out how they  are linked together and the related information flow within the decision-making  process. Indeed, the types, amounts and qualities of the exploited resources,  both tangible and intangible, have certainly an important bearing on the  workability of the firm, since they place technical and organizational  constraints, but a key ingredient is the aptitude of the team to achieve  cooperation and coordination in order to handle the flow of information. This  kind of synergy is essential in design practice, even more if we consider  sustainable design. In fact, contrary to other sector where different issues  are managed in a more or less autonomous way by team or specific experts,  environmental issues involve all the actors engaged with significant  reverberation in the decision-making process. Particular attention therefore is  directed to the design phases in which sustainable targets are set and in which  environmental experts and, eventually, outsourcing partners are involved within  the process also in relation to firm’s size. In addition, skills and  competences with the related tools and software will be matched, on one hand,  with design requirements (input) and, on the other, to final performance  (outputs). In this context, starting from the early stage of the project,  collaboration, coordination and communication play a key role in making sure  that firm resources turn first into “capabilities” (minimum ability) and later  into “maturity” (quality achieved by good practice).
Furthermore, in line with current tendencies that lead to consider  artefacts as small part of a larger networks, systems and environment (just to  think “Industry 4.0” and “Internet of things” trends), the life cycle approach  is stressed as an ongoing and future challenge for AEC firms, to take a  broadening of perspective and to avoid shifting problems from one life cycle  stage to another. To this end, during the selection of case studies, the  priority is given to the projects equipped with an LCA study, identifying the  background of the related experts, the type of information addressed and the  data sourcing. When LCA is applied to the project, the goal is to improve, by  means of the proposed framework, its forcefulness and usefulness in the design  process, while when it is not developed, the goal is to try to figure out how  it could be implemented within the design process and what are the information  already available for the tasks. Indeed, LCA method allows AEC firms to make  aware decisions, gain long-term perspectives and define the most effective and  efficient way to meet environmental requirement and decrease environmental impacts.
After the case studies experiences, the mappings fulfilled for every  firm in partnership aims to depict the design process of the project in  question, taking a life cycle perspective and focusing on environmental issues  and their role in the decision-making process. For this purpose, this type of  interview adopts direct means of communications, such as face to face questions  to the actors involved, as well as a close examination of the set of documents  related to the case study, provided by the same AEC firm but also by external  partners.