Optimizing Residential Buildings Desing Using Integrated Project Delivery (IPD) and Building Information Modeling (BIM): A Case Study in Peru

Abstract

Construction projects often exceed budgets and deadlines, evidencing the need for collaborative methodologies such as Integrated Project Delivery (IPD) and Building Information Modeling (BIM). This research evaluates their influence on the design stage of residential buildings through a case study in Peru, managed by an SME. The methodology includes: (1) diagnosis of management through documentary review and interviews, (2) proposal of tools based on BIM and IPD, and (3) validation through statistical analysis and a validation matrix. Nine typical problems were identified, such as deficiencies in plans, measurements and budgets, and poor planning. Eight optimization tools were proposed, including NEC4 ECC contracts, Trimble Connect, Revit, Navis-works, contractor integration, ICE Sessions, 3D, 4D, and 5D BIM models. The 3D model showed 0.48 interferences per m², the 4D facilitated the monitoring of progress, and the 5D optimized costs by 5.28%. The validation process highlighted the NEC4 ECC Contract, the integration of the contractor, and the 3D and 5D BIM models (Revit and Navisworks) as the most effective tools. This study provides evidence on the implementation of BIM and IPD to optimize the management of residential buildings.

1. Introduction

The construction industry has shown a weak performance compared to other industries, with only 5% of global projects being completed within the original budget and schedule [1]. Commonly used execution systems, such as Design-Bid-Build (DBB) and Design-Build (DB), present notable differences in performance. Research indicates that DBB projects typically experience delays equivalent to half of their original duration, while DB projects have shorter delays [2]. Furthermore, the lack of integration between project owners and project staff contributes to the failure of most projects to meet the performance requirements [3].

Although contract documents should be complete and accurate, in practice, they are often incompatible and incomplete, leading to the need for clarification during construction [4]. Project compatibilization is predominantly carried out in the traditional way by overlaying 2D CAD drawings [5].

The critical global situation in the construction industry is not isolated from the Peruvian reality [6]. According to the Report of Paralyzed Projects, published by The Peruvian Republic’s General Comptroller [7], it is revealed that 1746 projects have been paralyzed in the country. Deficiency in the design of technical files is one of the main causes [8]. The Southern Macro Region, which includes Arequipa, Apurímac, Puno, Moquegua, Cusco, and Tacna, has the largest concentration of paralyzed projects, with a total of 746 projects. According to Acero [9], there are many paralyzed projects in Tacna; such is the case of the Hipólito Unanue hospital, which had its contract signed in December 2015 with the Consorcio Salud Tacna for a total of S/279,291 with the expected completion of the work scheduled for 2019. However, to date, the infrastructure is paralyzed at an execution progress of 45.9% and its budget has increased to S/598,431.

Thus, it is evident that there is a global problem which includes Peru. This research addresses such issues considering the management and integration of projects in Peru. Sullivan, et al. [10] point out that the success of a construction project depends largely on the selection of the execution system. Since the design phase of a DBB project is completely independent of the construction phase, this results in significant efforts during the construction phase to resolve constructability issues and coordination requirements that were overlooked during the design phase [11]. These problems can be avoided with a more integrated approach in which all project stakeholders communicate and collaborate to develop a better design [12].

The Integrated Project Delivery (IPD) is one of the recent and rapidly implemented approaches that incorporates people, systems, commercial structures and actions into one single process, bringing together the talents and vision of all project participants to increase the value delivered to the customer, reduce waste and enhance efficiency, thereby promoting the success of the entire project [13,14,15]. Likewise, Building Information Modeling (BIM) represents the digital transformation of the construction industry, providing more accurate and efficient management at all stages of the project. Its value relies on collaborative 3D, 4D, and 5D models, which enable it to generate more precise deliverables and improve the visualization of the project before its execution. The 3D model enables the early detection and correction of interferences, reducing errors on site. As for the 4D model, it allows detailed monitoring of progress and foresight of possible delays. For its part, the 5D model provides optimization on cost management. Together, these models improve design efficiency, planning, and management and facilitate decision-making and information management [16].

Murguía [17] points out that, there is currently an increasing acceptance of BIM among construction professionals in Peru. However, despite the great willingness to use BIM, the actual usage still shows a significant knowledge gap, suggesting that there are still challenges to fully implementing BIM in practice. The Peruvian Ministry of Economy and Finance (MEF) [18] by means of Directorial Resolution No. 0002-2021-EF/63.01 approved the Implementation Plan and Roadmap of the BIM Peru Plan, as well as the National Competitiveness and Productivity Plan 2019–2030, approved by Supreme Decree No. 237-2019-EF, which establishes the “Policy Measure 1.2: BIM Plan”, with the main objective of progressively incorporating the collaborative methodology of digital information modeling for construction in the public sector.

Given the above, this research proposes the following hypothesis: through the implementation of BIM and IPD methodologies, it will be possible to optimize the design stage in residential building projects. IPD and BIM are both considered independent variables, and the Design Stage in Management is the dependent variable. The objective of the research is to evaluate how BIM and IPD methodologies, in an integrated manner, will optimize the design stage in residential building projects. Therefore, the study is based on literature reviews throughout Section 2, followed by Section 3, which discusses the developed methodology in a Peruvian case study, results are presented in Section 4, followed by their discussion in Section 5, and finally, Section 6 includes the conclusions.

The originality of this research lies in its methodological approach, which includes a detailed diagnosis, a specific improvement proposal and a subsequent validation of the results. Unlike other studies, this paper analyzes its integration and its impact on a specific case. In addition, the proposed improvements respond to particular conditions of the context studied, providing a differential value with respect to previous research.

2. Background

This section addresses a review of the most relevant research regarding IPD and BIM methodologies, which both have proven to be useful for construction projects.

Table 1. IPD and BIM state of the art based on similar approaches to the case study and their main data collection methods.

Author	Approach	Main Data Collection Methods
	Importance or Relevance	Surveys	Interviews	Case Studies	Questionnaires	Literature Review
Franz, et al. [19]	Team integration and group cohesion	X
Laurent and Leicht [20]	Cross-functional teams in IPD projects	X		X
Ling, et al. [21]	IPD practices			X	X
Buk’hail and Al-Sabah [2]	The willingness to implement IPD				X	X
Othman and Youssef [22]	Framework for the implementation of IPD approach at the design stage			X	X	X
Alqahtani et al. [23]	Bidding process and procurement regulation for IPD implementation.	X				X
Alinezhad et al. [24]	Benefits of implementing the IPD approach			X		X
Ajmal and Rajasekaran [25]	Construction and engineering contracts, NEC4 ECC contracts.			X		X
Yabar-Ardiles, et al. [26]	Public building and construction contracts, NEC4 ECC contract.			X		X
Lau, et al. [27]	Challenges that hinder the widespread implementation of NEC	X	X
Khanna, Elghaish, McIlwaine and Brooks [15]	Viability of implementing IPD along with BIM and TIC		X			X
Bravo and Mendoza [28]	IPD and VDC tools.	X		X
El Asmar, et al. [29]	Performance of IPD projects	X		X		X
Mesquita, et al. [30]	Use of BIM for modeling and interference analysis			X
Dos Santos, et al. [31]	BIM methodology is used to ensure project compatibility			X
Yañez [16]	Challenges associated with the implementation of BIM		X	X		X
Akter, et al. [32]	Impacts of using BIM as a construction management tool	X		X

summarizes the literature consulted in indexed journals about IPD and BIM.

Table 1 presents a detailed review of the literature, highlighting the different approaches when implementing BIM and IPD, as well as the main collection methods. Among these methodologies, IPD stands out for its fundamental principles: (1) early involvement of key participants to achieve early optimizations, (2) shared risks and benefits according to project results to motivate improvements, (3) joint project governance to empower the team, (4) reduced blaming exposure to encourage the development of new ideas, and (5) jointly developed and validated goals to engage the team.

Research such as that of Franz, Leicht, Molenaar, and Messner [19]; Buk’hail and Al-Sabah [2]; and Ling, Teo, Li, Zhang, and Ma [21] have shown that IPD significantly improves cost, schedule, quality, and project performance results. Laurent and Leicht [20] emphasize the importance of forming these teams from the earliest design phases to ensure project success. In this context, NEC4 ECC contracts are aligned with IPD principles and their importance for good management has been pointed out by Ajmal and Rajasekaran [25].

The other relevant methodology is BIM, which emerges as a key tool of the IPD. BIM interoperability with other digital tools is critical for more accurate and efficient management. According to Bravo and Mendoza [28]; Maciel, de Souza, and Oliveira [5]; and Khanna, Elghaish, McIlwaine, and Brooks [15], BIM improves planning, estimation, and cost control, and facilitates early identification of interferences and incompatibilities in drawings, thus optimizing the budget.

Reviewed studies, including those by Alinezhad et al. [24]; Khanna, Elghaish, McIlwaine, and Brooks [15]; and Bravo and Mendoza [28], conclude that the implementation of IPD and BIM offers significant benefits such as transparency, effective coordination, early cost awareness, reliable pricing, and improved quality. Tools for modeling and measurement such as Revit and Navisworks for resolving interferences automate tasks, save time and reduce costs, improving budgetary accuracy.

Despite the obvious benefits, the construction industry faces significant challenges in implementing IPD and BIM. Buk’hail and Al-Sabah [2] identify barriers such as unwillingness to sign contracts that included liability waivers and that excluded IPD’s organizational hierarchical structure. Othman and Youssef [22] highlight the existence of communication and collaboration issues among stakeholders. Khanna, Elghaish, McIlwaine, and Brooks [15] point out the resistance to change and lack of experience as the main obstacles to change. Yañez [16] determines that not all professionals have the same level of knowledge about BIM, that design is not carried out directly in 3D, and that supervision does not yet have direct involvement in BIM. To overcome these challenges and maximize the use of these methodologies, it is essential to examine their application in projects.

Thus, this research focuses on implementing BIM and IPD methodologies in the design stage of a residential building project in order to achieve management optimization, which underlines the relevance and potential of this research as a proposal in this field.

3. Materials and Methods

The methodology of the present study is based on the analysis of a single case study using a mixed approach which combines qualitative and quantitative methods. From a qualitative perspective, an analysis of information management is carried out through a bibliographic review, which facilitates the formulation of improvement proposals and tools to address the deficiencies detected. From a quantitative approach, specific units such as interferences, metrics and costs are measured (126 items analyzed).

This research is of an applied nature since it seeks to obtain new knowledge to offer practical solutions to specific problems. The study design is non-experimental. The level of research is descriptive and is considered transversal since it is carried out at a certain time.

IPD, BIM, and management optimization at the design stage are the three most relevant variables. Management at the design stage, which depends on IPD and BIM, is the dependent variable, while IPD and BIM, which do not depend on other variables, are both independent variables.

Table 2. Objectives and Methods.

Section	Objectives	Methods
Section 4.1	To conduct a diagnosis on the management of residential building projects for the SME.	A. Analysis of management practices in SME residential building projects through documentation review and semi-structured interviews. B. Analysis of an SME residential project through documentation review and semi-structured interviews. C. Identification of typical issues in the SME.
Section 4.2	To propose an optimization of the SME by integrating IPD and BIM.	A. Literature review on BIM and IPD tools that can be implemented to improve management. Case study with description of its utilization.
Section 4.3	To validate the proposal for optimization of IPD and BIM integration.	A. Validation statistical analysis via Z-test. B. Elaboration of a validation matrix for the implementation of improvement tools integrating BIM and IPD.

details the methods to be applied in accordance with the specific objectives of the study, which are based on the literature review presented in the previous chapter.

According to Table 2, the design stage is optimized by integrating IPD and BIM in a Peruvian case study. The reasoning behind selecting this case is that it represents the limited adoption of these methodologies in Peru, especially among small and medium-sized companies in the construction sector, which constitute a significant part of the industry. Initially, a diagnosis of the Small and Medium-sized Enterprise (SME), which manages projects in a traditional manner, is carried out. Then, an improvement is proposed by integrating IPD and BIM into an SME project, with the objective of adapting this proposal to other similar projects within the same SME and to other SMEs with similar characteristics. To evaluate for optimization with BIM, statistical indicators are used such as interference indicators per square meter. The comparison of the variability in the metering of the traditional methodology versus the BIM methodology and the probable cost of the project is quantified and validated by Z-tests. The cost-effectiveness of BIM and IPD methodologies is also analyzed.

4. Results

4.1. Diagnosis

4.1.1. SME Description

The SME is a construction company located in Tacna, Peru, that specializes in residential building projects, with the mission of providing the population of the city with access to proper housing, and with the vision of creating adequate living spaces in collaboration with the government through the use of bonds destined for this purpose. Currently, the SME has completed the delivery of eleven projects, while four others are under implementation and three are pending. The management of its projects follows a traditional approach which comprises several stages. Initially, the planning and basic studies stage is carried out, followed by the preparation of the preliminary project, after which the basic design and construction design are developed. Simultaneously, the corresponding permits are processed with the corresponding public entities. Subsequently, the measurements, construction budget and schedule are prepared. With all this documentation, the financing is processed with the financial institution.

Once these stages are completed, the contract is formalized with the contractor, with the SME assuming 64% of the work and the contractor 36%. A traditional contract is used to establish the contract amount, terms, penalties, methods of payment, project manager, and annexes that include blueprints, technical specifications, descriptive reports, measurements, construction budget and schedule. Upon completion of that stage, execution of the work begins, the progress of which is monitored by means of monthly valorization reports until the project is completed.

The SME’s main resources include both human and material resources. The company has a staff of 10 employees, while the contractor has 13 employees. In addition, they rely on the collaboration of 10 service providers to carry out operations efficiently. SME’s organization chart is composed of the General Management, Deputy General Management, Administration and Finance (accounting, logistics and treasury), and the Technical Area (architecture and engineering: projects and project manager).

Regarding material resources, the SME has 7 computers, 2 laptops, 1 plotter, and 3 printers. All workstations operate with the Windows 10 operating system. The software applications used include AutoCAD 2020, Microsoft Excel 2019, SketchUp 2022, Lumion 2022, Microsoft Word 2019. Regarding information management, data and document management is mainly carried out manually and through Google Drive, where all project documentation is stored and shared with each area of the SME. Communication is carried out through WhatsApp groups, temporary meetings, and phone calls.

4.1.2. Description of the Case Study

The documentation of the SME projects was reviewed and four projects were identified, such projects presented significant deviations in budget and deadlines with respect to the project design. These inconsistencies showed deficiencies in the SME management system. These are detailed in Figure 1 and Figure 2.

Figure 1 shows the comparison between the contract amount and the executed amount of four SME projects. The variation margin between these amounts ranges from −3.45% to −5.13%, with Project D having the largest margin. These results are consistent with the findings of Asvadurov, Varilla, Brindado, Brown, Knox, and Ellis [1], who reported cost overruns of up to 37% in global projects.

Figure 2 presents the comparison between the contractual schedule and the executed schedule for the same four projects. The percentage of variations in schedule varies between −26.29% and −39.67%, with Project D showing the largest gap. These findings are consistent with those reported by Asvadurov, Varilla, Brindado, Brown, Knox, and Ellis [1], who found gaps of up to 53% in global projects.

Based on the indicators presented, Project D was chosen as the case study because it was the one that showed the greatest variation, which allows an in-depth analysis of the causes and possible solutions. This project is a residential building in Tacna, Peru, of 5 levels plus a rooftop, with a 128 m² lot and a roofed area of 617.87 m². The first level includes 2 garages, 1 storage room, 1 solid waste room, 1 staircase, and 1 apartment. The second, third, fourth, and fifth levels have a typical layout with 1 staircase and 2 apartments. The roof terrace consists of 1 rooftop terrace and 1 area for drying clothes. The structure is framed with confined masonry. The sanitary installations include a pumping system, cold water distribution, and drainage networks. The electrical installations include independent single-phase current for each apartment and data and communications outlets. Project development was carried out in the traditional manner and under a traditional contract. The programmed budget was S/834,376.79, while the executed budget reached S/877,180.32. The programmed deadline was 305 days, and the final execution deadline was 426 days.

4.1.3. Typical Management Problems

Following the analysis of the SME documentation and the case study, 11 interviews were conducted with different project participants including contractors, professionals from different specialties, labor personnel, and suppliers. The following question was formulated to them: What do you consider to be the main reasons for cost overruns and delays in the SME projects? Based on all this information, the following management problems were identified:

• P1: Deficiencies in the blueprints.
• P2: Deficiencies in the measurement and budget.
• P3: Weak team communication, coordination, and collaboration.
• P4: Modifications and/or reworks.
• P5: Existence of hidden flaws that generate additional work.
• P6: Cost overruns in the construction process.
• P7: Delays due to poor planning in material supply and errors in material purchasing.
• P8: Lack of clarity and transparency in the contract and its clauses.
• P9: Lack of incentives for good practices.

It is evident that most of the identified problems could have been avoided during the design stage. Therefore, we will focus on solving these problems by incorporating tools from the BIM and IPD methodologies.

4.2. Optimization Proposals

With the purpose of addressing the problems identified in the diagnosis, the tools of both BIM and IPD methodologies, which were compiled through a detailed bibliographic review in Section 2, are presented below. It should be mentioned that these tools allow for better project management and can be integrated into a working model that includes BIM and IPD.

4.2.1. H1: Contractual Management–Standardized Contract

To develop an optimal project, it is crucial to have clear and well-defined contracts. This tool is related to the 1D dimension of BIM, as well as to aspects of project conception under IPD standards.

Based on the criteria of Yabar-Ardiles, Sanchez-Carigga, Vigil, Málaga, and Zevallos [26],

Table 3. Comparison of SME contract and NEC4 ECC tools and incentives.

Indicator	SME Case Study Contract
Clarity and simplicity	Specifications
Number of clauses	The contract stipulates seven clauses.
Linguistic level	The contract primarily uses legal language.
Contract parties	The contract only mentions the Client, which is the SME, and the contractor. There is no direct mention of the other parties and their responsibilities under the contract; only the construction manager is mentioned in the sixth clause.
Stimulus for good management	Specifications
Payment	The contract establishes monthly appraisals as a form of payment.
Incentives	The contract does not stipulate any incentives for good practices on behalf of the contractor or other contract agents, only penalties for unjustified delays.
Communication systems	The contract does not mention any type of communication system or mechanism that requires the parties to make notifications through the contract.
Early warnings	The contract does not stipulate any early warning mechanism.
Conflict resolution	Two dispute resolution mechanisms are contemplated, conciliation or arbitration.
Risk allocation	The contract does not stipulate risk allocation.

analyzes and identifies the deficiencies in the case study contract of Project D, using the incentives and tools recommended by NEC4 ECC as a reference. (New Engineering Contract—Engineering and Construction Contract).

Table 3 presents the shortcomings of the traditional contract in the case study in terms of clarity and stimulus for good management. Some clauses contain insufficient information, which can lead to disputes, and there is no adequate risk distribution. These problems coincide with the key aspects that NEC4 considers essential for good management. It is therefore recommended to implement NEC4 ECC clauses to address these deficiencies, supported by studies such as the Managing Reality compendium [33] and Yabar-Ardiles, Sanchez-Carigga, Vigil, Málaga, and Zevallos [26], which also suggests their use to foster collaborative environments. The clauses are shown below.

• Communication (C. 13).

Establishes a written communication system with defined response times for notifications such as early warnings and inconsistencies, among others. Each party maintains its own record to facilitate problem prevention and resolution.

• Early Warnings (C. 15).

Allows any party to notify events that may affect the price, schedule, or execution of the project. Notification should be made as soon as the event becomes known so that meetings are held to manage changes efficiently and failure to do so may result in penalties.

• Compensation Events (C. 60).

Covers situations where the contractor is entitled to compensation, as long as the problem is not attributable to the contractor. The contractor must submit to the Project Manager the corresponding solution and quotation for the Compensation Event. The Manager will evaluate this proposal and, if necessary, instruct the contractor to consider more efficient alternatives. Timely notifications of these events are essential to avoid penalties and to promote a collaborative resolution of the problems.

• Incentives.

Clause X12 promotes multi-party collaboration and rewards compliance or improvement of key performance indicators (KPIs). X20 establishes incentives for the contractor based on KPIs defined by the counterparty. X6 provides incentives for early completion of work. Main Options C and D, which operate under a Target Price Contract, compare the final price of the works with a target price set in the contract. If there is a positive balance in this comparison, it is distributed between the parties as agreed.

• Dispute Avoidance Board (W3).

Offers dispute mitigation and resolution options, with it as the first method. This board visits the project site, inspects the work, offers recommendations, and resolves disputes before they are formally referred to a court of law.

The flexibility of NEC4 ECC facilitates the integration of BIM and IPD through clauses such as C.16, which fosters collaboration between the parties from the beginning of the project; X10, which regulates information management; X20, which regulates shared objectives and performance bonuses; and C.Z which allows contractual aspects to be customized according to the needs of the project.

The implementation of these improvements will contribute to establishing contractual clarity with defined responsibility, incentivizing good practices, optimizing project performance, and reducing cost overruns and delays through compensation and exchange control mechanisms.

4.2.2. H2: Common Data Environment (CDE)

Communication is fundamental to establishing collaborative environments. In the case study, Drive, WhatsApp, and emails were used; however, with the implementation of BIM models, there is a need to improve this aspect. The Common Data Environment (CDE) is the leading platform for documentation, quality control, and project information management. It aims to streamline model reviews, facilitate change management, improve communication, and foster collaboration, as well as ensure information security and prevent document duplication. It is crucial that the CDE is available to all stakeholders, with clearly defined roles and access levels.

In this context, according to the literature reviewed, Trimble Connect, a cloud-based platform, was recommended. It meets these requirements and organizes all project documentation, 3D models, 2D drawings, PDF files, spreadsheets, and RFIs, in a single accessible location. This eliminates the need to compress and email files, ensuring that all team members work with the latest version of documents and models. This reduces errors and ensures transparency, accessibility, and traceability of project information, improving collaboration by allowing an overview and specific details. In addition, all movements are registered, which facilitates the control of changes and updates.

Trimble Connect Sync allows you to synchronize files from your computer, network drive, or mobile device to the cloud, keeping everything up to date in both locations. The To-Do tool improves task management and project communication by allowing comments, questions, and concerns to be documented and assigned to team members, who receive email notifications. Tasks are customized with titles, descriptions, due dates, and other relevant information, which can be linked to specific objects in the model reviewed by all participants. Trimble Connect offers a free version with 10 GB of cloud storage; for more capacity, professional licenses must be purchased.

Its implementation improves team communication and coordination, ensuring access to up-to-date information. In addition, it avoids unnecessary modifications and rework by maintaining a single source of truth, reducing delays caused by poor planning, and optimizing workflow.

4.2.3. H3: Software

The efficiency of project development depends to a large extent on the technical capabilities of the software used. In the case study, a traditional AutoCAD approach was used for documentation development, so it is essential to have adequate resources to ensure trouble-free development. According to the literature reviewed, there are several key software categories in this process, such as modeling, coordination, measurement and budgeting, scheduling, and visualization. Tools such as Revit and Navisworks are prominent examples in the construction field.

Revit is the leading platform for building BIM information models. Its ability to automatically coordinate project changes and share a database of files among multiple users makes it indispensable.

On the other hand, Navisworks stands out as a BIM model viewer that covers all phases of the project. It facilitates the interoperability of 3D models during design and construction, improving visualization and interference detection. Its ability to read almost any 3D file format and handle large files makes it a crucial tool for project management.

These tools were applied in the Project D case study, demonstrating that the use of these tools contributes to minimizing deficiencies in plans, measurements, and budgets through precise and coordinated models. Reduce modifications and rework by detecting interference in the design phase. Avoid hidden defects that generate additional work, improving the quality and consistency of the project.

4.2.4. H4: Work Teams

In projects, it is essential that teams have complementary skills, share a common purpose, pursue performance objectives, and are mutually accountable for the result. In the case study, the work team during the design stage did not include the contractor up until the execution of the work, which is a practice that could be improved. We reviewed the literature and recommended that the team should consist of, at a minimum, the owner or a representative, an architect or engineer, a designer, and a general contractor or project manager. Early inclusion of the contractor facilitates the incorporation of diverse perspectives, optimizes deliverables, and reduces the need for later modifications.

Likewise, it is necessary to have trained professionals with experience in BIM and IPD methodologies software. To ensure effective management of these methodologies, an adequate budget should be allocated for the continuous training of these professionals.

Early contractor integration contributes to: improving project planning and execution; reducing deficiencies in plans, measurements, and budgets by incorporating construction experience from the beginning; reducing cost overruns in the construction phase; and avoiding delays due to poor planning, providing a more realistic view of execution.

4.2.5. H5: ICE Sessions

The Integrated Concurrent Engineering (ICE) sessions are fundamental to successful project development. In the case study, they were limited to temporary meetings, indicating the need to improve this approach. The literature was reviewed and is recommended that ICE Sessions be held face-to-face in a suitable space, equipped with chairs, projectors, large tables, electrical connectors, lighting and ventilation control, and a whiteboard. This environment should encourage active participation and use the best technological tools available to ensure transparency and trust among participants.

ICE sessions should be held at least once a week, with the active participation of all those involved in the project. During the design phase, the frequency can be increased twice a week or even daily, depending on the size of the project. These meetings allow the integration of all project specialties and improve overall understanding, thus optimizing the design procedures.

Clear agendas should be established to align the team with the project objectives. Agendas should be shared in advance with everyone involved to allow for brainstorming solutions in case problems arise. Pre-sessions help to reduce latency times and to make faster decisions.

ICE sessions enable: better decision-making and early problem-solving through real-time interdisciplinary meetings; optimization of communication, coordination, and collaboration by bringing all key parties together in structured sessions; reduction in modifications and rework by identifying errors before execution; reduction in delays due to poor planning, speeding up decisions, and approvals.

4.2.6. H6: 3D Model

The three-dimensional representation of the drawings, together with the parametric representation of each building component, forms the 3D Model. In the case study, a traditional approach with 2D drawings was used; therefore, it is recommended to implement 3D Models to improve visualization, coordination, project presentation, design review, and incompatibility detection, thus optimizing planning and productivity control.

Based on the criteria of Maciel, de Souza and Oliveira [5], Project D plans were modeled in Revit, in separate templates for each specialty, with linkage between them. This methodology allowed keeping the templates lighter so that they would not interfere with the computer processing. In addition, by separating the specialties, the possibility of accidental changes in the models of other disciplines was prevented, a risk that can arise when everything is modeled in a single template. The models of each specialty are shown in Figure 3.

After completing the modeling, the models were integrated into Navisworks for interference detection, identifying recurring problems such as overlapping windows, doors, pipes, and devices with structural elements. These findings support previous studies that highlight the importance of BIM in the compatibility of multidisciplinary projects. It is crucial to prioritize interferences according to their impact. To solve these problems, ICE sessions should be scheduled with all stakeholders to make shared decisions.

In Figure 4, percentages of interferences between specialties are shown, 64 interferences (22%) for Structures vs. Architecture, 103 interferences (35%) for Structure vs. Sanitary installations and 128 interferences (43%) between Structure vs. Electrical installations, for a total of 295 interferences.

As shown in Figure 4, “Structure VS Electrical Installations” interferences represent the highest percentage, mainly due to the presence of pipes and devices in structural elements. To minimize these interferences, it is essential to coordinate the installation of electrical systems with that of the structures. Placing outlets, switches, and switchgear on plates, columns, and beams should be avoided, and instead, they should be located on the walls.

On the other hand, Maciel, de Souza and Oliveira [5] identified in their study that the highest number of interferences was between Structures vs. Sanitary Installations, which also underlines the importance of using BIM methodology for better coordination.

The interference per square meter indicator was calculated considering the total interference detected between the total roofed area of the project, as shown in

Table 4. Interference per square meter.

Data
Roofed area (m2)	617.87
Interferences (No.)	295
Interferences (m2)	0.48

.

Table 4 shows that there are 0.48 interferences per square meter of roofed area, which indicates a significant amount in relation to the total area. This finding is crucial to assess the impact on the budget, as it highlights the need to identify possible modifications that could have affected the original budget. Systematic analysis by overlaying models in Navisworks facilitates the early detection of problems and contributes to more efficient project execution by reducing rework and delays during construction.

The integration of the 3D model enables a reduction of deficiencies in plans, measurements, and budgets, improving the precision of the design. It also enables the minimization of modifications and rework by detecting errors before execution and avoids hidden defects that generate cost overruns, through verifications prior to the start of the work.

4.2.7. H7: 4D Model

Time factor determines a sequence of execution for each element of the project, which allows for controlling its dynamics and anticipating possible difficulties, thus increasing performance and complying with the established deadlines. Implementing the 4D model in the planning and control of a project can be of great help to ensure compliance with time and budget, being essential to constantly monitor the progress of the project.

Figure 5 shows the monthly sectorization of the structure specialty of Project D, according to the contractual schedule. The colors indicate the monthly progress of the project. This methodology can also be applied to other specialties.

Sectorization or 4D simulation allows the generation of project progress control reports using the BIM model. This approach is more valued by clients compared to a Gantt chart, as it facilitates a better understanding and visualization of project progress.

The 4D model contributes to: visualizing and optimizing the construction sequence, improving planning; reducing delays due to poor planning, by anticipating conflicts and adjusting scheduling; reducing modifications and rework; simulating the construction process before execution; optimizing team coordination, by visually showing the interaction of tasks over time.

4.2.8. H8: 5D Model

5D Model covers the obtaining of measurements and cost estimation, allowing precise control over the financial information and improving the profitability of the project’s investment. After generating the 3D models of the different specialties the D project was measured with BIM in order to compare the measurements obtained with the data of the technical file.

A total of 126 items were analyzed, of which 34 items are for structures, 22 for architecture, 47 for sanitary installations, and 23 for electrical installations.

Table 5. Variation of items by specialty.

Specialty	Total Items	P. with Variation	P. Without Variation	Percentage
				P. with Variation	P. Without Variation
Structures	34	34	0	100.00%	0.00%
Architecture	22	18	4	81.82%	18.18%
Sanitary Installations	47	28	19	59.57%	40.43%
Electrical Installations	23	13	10	56.52%	43.48%
Total	126	93	33	73.81%	26.19%

details the variation of the items by specialty.

As shown in Table 5, the specialty with the greatest variation is structures, followed by architecture, and more than 50% of all specialties have variation, which is a detrimental factor for the budget.

• Analysis of item variation.

Table 6. Items variation.

Item	Und	N° of Items	Percentage (%)
Total project items analyzed	und	126	100.00%
Total items with variation	und	93	73.81%
Total items without variation	und	33	26.19%

shows the total number of project items and the items with variation in the measurement, comparing the BIM methodology, and the traditional methodology.

Of the total number of items analyzed with the BIM methodology, 73.81% (93 items) show variation with traditional metrics, and only 26.19% (33 items) show no variation at all. These findings show the accuracy and efficiency of the use of BIM in the management of costs and measurements within the project.

• Cost Comparison

A comparison was carried out between the costs of the traditional methodology (items extracted from the file), and the cost obtained by using the BIM methodology. It was observed that the items with variations in the measurement also experienced changes in the costs. This is detailed in

Table 7. Comparison of total costs by specialty.

Specialty	Traditional Methodology	BIM Methodology	Difference
Structures	S/367,773.24	S/362,032.92	S/5740.32
Architecture	S/304,190.49	S/270,690.30	S/33,500.19
Sanitary	S/58,642.92	S/59,213.74	-S/570.81
Electrical	S/73,823.83	S/69,987.36	S/3836.47
Total	S/804,430.48	S/761,924.32	S/42,506.16

.

Table 7 shows that the total cost of the project, according to the technical file, which is S/804,430.48; while the cost using BIM tools is S/761,924.32, which represents a difference of S/42,506.16. This difference indicates an optimization of 5.28% with respect to the traditional method. In comparison, Chirinos and Pecho [34] reported an optimization of 1.97%, which reinforces the effectiveness of BIM implementation in cost optimization.

The use of the 5D model allows: More accurate estimates throughout the project. Reduction of cost overruns, by linking work quantities with budgets in real time. Avoid costly modifications and rework by detecting inconsistencies from the design phase. To promote good practices in the financial management of the project.

• BIM and IPD Profitability Analysis

Through

Table 8. BIM and IPD implementation cost.

Description	Quantity
Training Cost	S/4247.36
Modeling and management cost	S/4350.00
BIM and IPD implementation cost	S/8597.36

and

Table 9. Return on Investment Calculation (ROI).

Description	Quantity
Direct Cost Adjustment with BIM	S/42,506.16
BIM and IPD Implementation Cost	S/8597.36
Net income	S/33,908.80
ROI	394.41%

, the estimated cost of implementing the BIM and IPD methodologies for the case study was analyzed. The implementation of BIM and IPD requires previous knowledge, so a training cost will be considered. This cost was obtained from the course “Project Management through IPD and BIM” of the Continuous Education Center of ESPOL.

Moreover, the cost of modeling and management of the application of the BIM methodology and the extraction of metrics in Revit 2023 software is detailed, the hours worked in the development of the BIM model of the case study were counted, which were 10 weeks (250 h) with a working day of 5 h per day. A monthly salary of S/3341.00 was assumed according to Diar Ingenieros S.A., according to a work shift of 48 h per week for 4 weeks, resulting in a rate of S/17.40 per man hour.

With all this data, it is possible to calculate the return on investment (ROI) of the implementation of BIM and IPD methodologies, which will allow us to evaluate their profitability. ROI according to Cabrera and Quiroz [35] is determined by relating net income to the cost of implementation.

Table 9 shows a return-on-investment percentage of 394.41%, which means there is a return of S/3.94 for each S/1.00 invested in the implementation of BIM and IPD. In comparison, Cabrera y Quiroz [35] reported a 109% return for the BIM methodology. This suggests that the BIM and IPD methodologies offer a significantly higher return compared to the traditional methodology.

4.3. Validation

4.3.1. Statistical Analysis

For the validation of the optimization of the costs of the 126 items analyzed in project D, a Control Group (CG) was established following the criteria of Ureta and Chileno [36], this group was formed from a manual measurement prepared by the authors, which, after three rigorous reviews, was approved as a reference for the study. The costs obtained through the BIM methodology and the technical file (TF) developed with CAD were compared with this Control Group to evaluate their accuracy, obtaining percentages of variation in each of the 126 items analyzed. Figure 6 shows the percentages of variation of the technical file and BIM in relation to the Control Group. The results show that the technical file presents greater errors, while the BIM methodology offers more accurate data, which supports its effectiveness in cost optimization.

With the data presented in Figure 6, the measurement and standard deviation of the percentages of variation were calculated. Since the study analyzed a sample of 126 items (n1 = 126), a unilateral left-tail test (Z-test) was used. This analysis made it possible to measure the accuracy of the information obtained using the traditional methodology and the BIM methodology, with a significance level of α = 0.01, which corresponds to a confidence level of 99%. With 125 degrees of freedom (DF). The hypothesis posed is shown in

Table 10. Hypothesis test for two samples.

Hypothesis	Symbol	Description	Expression	Decision Rule
Alternative H.	Ha	With BIM methodology, costs are optimized.	µ1 < µ2 1	IF REJECTED Ho Si: Zk < Zα
Null H.	H0	With the BIM methodology, costs are not optimized.	µ1 ≥ µ2 1	IF ACCEPTED Ho Si = Zk ≥ Zα

¹ µ1 represents the sample average percentage change in BIM costs relative to the Control Group; and µ2 is the sample average percentage change in Technical File costs relative to the Control Group.

and

Table 11. Data for test statistics.

Sample	n.	Media	Standard Deviation
% Variation BIM/G.C.	126	x1 = 2.96%	σ1 = 4.59%
% Variation E.T./G.C.	126	x2 = 46.79%	σ2 = 145.71%

.

With this data, the calculation was made using the following statistical formula for the difference of two means:

$$Zk={\displaystyle \frac{x1-x2}{\frac{\sqrt{{\sigma 1}^2}}{n1}+\frac{{\sigma 2}^2}{n1}}},$$

(1)

Applying the formula, a value of Zk = −3.38 was obtained. On the other hand, the value of Zα = −2.33 was obtained from the standard normal distribution table with negative Z-scores, considering a confidence level of 99% (α = 0.01).

Figure 7 shows that the obtained value Zk = −3.38 is less than the critical value Zα = −2.33, which allows the null hypothesis to be rejected and the alternative hypothesis to be accepted. These results confirm that the BIM methodology optimizes costs and provides more accurate data compared to the technical file prepared using the traditional method.

4.3.2. Validation Matrix

After examining the eight proposed tools,

Table 12. Proposals for improvement and implementation.

Proposed Tools		Problem to be Solved
		P1	P2	P3	P4	P5	P6	P7	P8	P9
H1	Standardized Contract: NEC4 ECC				X		X	X	X	X
H2	CDE–Trimble Connect			X	X			X
H3	Software: Revit and Navisworks	X	X		X	X
H4	Work Teams-early contractor integration	X	X				X	X
H5	ICE Sessions			X	X			X
H6	3D BIM Model	X	X		X	X
H7	4D BIM model			X	X			X
H8	5D BIM model		X		X		X			X

shows how each one addresses and solves the management problems identified in the diagnostic, with the objective of improving management in future SME projects.

Table 12 shows that the H1, H3, H4, H6, and H8 tools address most of the identified problems, in general, these eight tools were strategically selected to comprehensively address the nine typical management problems in construction projects. The H1 Tool integrates effectively with BIM and IPD methodologies, favoring digital collaboration and design optimization. In addition, it promotes contractual transparency and clarity, joint decision-making, and offers incentives for good practices, which encourages the commitment of the actors involved.H2 and H5 tools are key to improving communication, coordination, and collaboration between teams, avoiding modifications and rework and reducing delays due to poor planning. Tool H3 highlights the importance of using appropriate software, such as Revit and Navisworks, for the effective implementation of BIM models, which contributes to optimizing management. Tool H4 stresses the need to clearly define the team members and ensure their active collaboration at each stage of the process, including the contractor from the design phase allows for better project planning and execution. H6, H7, and H8 are essential from the early stages of the project all the way through to completion. The 3D model is the basis for the 4D and 5D models. These tools not only improve the quality of deliverables but also optimize project scheduling, metrics, and costs, ensuring more accurate outputs.

The main contribution of this study lies in the identification of the most recurrent management problems in residential building projects and in the formulation of concrete proposals for improvement based on the collaborative methodologies, IPD and BIM. In addition, the validation of these proposals demonstrates their viability and provides a practical approach that can be applied in similar contexts, offering a differentiated value compared to previous studies.

5. Discussion

By examining the case study, nine key problems have been identified in the traditional management of residential buildings. These problems coincide with those reported by Othman and Youssef [22]; Yabar-Ardiles, Sanchez-Carigga, Vigil, Málaga, and Zevallos [26]; Ajmal and Rajasekaran [25]; and Dos Santos, Ferreira, and Ferreira [31], who also identified similar problems. The concurrence with previous studies underscores the persistent shortcomings in traditional management.

Eight optimization tools are proposed from the integration of IPD and BIM such as the implementation of NEC4 ECC collaborative clauses in traditional contracts, Yabar-Ardiles, Sanchez-Carigga, Vigil, Málaga, and Zevallos [26] and Wright and Fergusson [37], support this proposal, indicating that NEC ECC improves project management, provides contractual clarity and fosters proactive relationships, thus optimizing project management. The Trimble Connect CDE tool simplifies coordination and information exchange on BIM projects, Gehry, et al. [38] emphasize that this tool improves constructive clarity, reducing costs and deadlines. Using Revit and Navisworks within a BIM environment excels because of their interoperability and ability to integrate information from various disciplines, according to Akter, Datta, Islam, Tayeh, Sraboni, and Das [32], these tools significantly improve construction quality and safety. Regarding the Work Teams, the case study team did not have contractor intervention until the actual execution of the work, this approach should be improved; the adoption of IPD principles by integrating the contractor from early stages is supported by authors such as Franz, Leicht, Molenaar, and Messner [19] and Laurent and Leicht [20] who highlight that their integration significantly improves performance in terms of costs and project timelines.

With regard to ICE sessions, it is recommended to implement them regularly, at least once a week, and to increase their frequency during the design stage, as this practice will improve team collaboration and communication, Laurent and Leicht [20] also suggest weekly or more frequent sessions in order to optimize management. Analysis of the 3D Model revealed 295 interferences, equivalent to 0.48 interferences per square meter of roofed area. These findings suggest that the use of BIM facilitates the identification and correction of interferences prior to project execution, resulting in cost and time savings. Consistent with this, Dos Santos, Ferreira and Ferreira [31] confirm that project compatibilization through BIM makes it possible to detect and correct interferences before the execution phase, thus improving project management. The integration of the 4D Model facilitates decision-making and improves communication by allowing visualization of the construction sequence over time. According to Martins, et al. [39], the 4D Model optimizes communication between teams at different stages of the project. In relation to the 5D Model, the study revealed that 73.81% of the items analyzed showed variations in metrics and costs. BIM methodology achieved an optimization of 5.28%, equivalent to savings of S/42,506.16. Chirinos and Pecho [34] found an optimization of 1.97%, demonstrating that the BIM methodology reduces the margin of error and optimizes costs through a more accurate quantification of the measurements. Profitability analysis showed a net profit of S/33,908.80 and a return of 394.41%, indicating that each S/1.00 invested in BIM and IPD generated a return of S/3.94. Cabrera and Quiroz [35] found a 109% return, suggesting that these methodologies are cost-effective.

The validation of the cost optimization was verified with the Z statistical analysis that confirmed the cost optimization with a level of reliability of 99%. The Matrix of Validation demonstrated that all proposed tools address management problems, with the 3D BIM Model solving the most problems. Khanna, Elghaish, McIlwaine and Brooks [15] emphasize that the integration of IPD and BIM methodologies improves coordination and transparency, optimizing costs and deadlines. Therefore, the implementation of these methodologies will improve the management of future projects.

It should be mentioned that there are additional BIM dimensions under development, such as BIM 6D (energy and sustainability), BIM 7D (maintenance and asset management), and the emerging BIM 8D (safety), BIM 9D (Lean Construction) and BIM 10D (construction industrialization), as well as the City Information Model (CIM). As technology evolves, it is suggested to consider the integration of new technologies such as artificial intelligence (AI) and Machine Learning with IPD and BIM for more efficient processes. This research highlights the benefits of BIM and IPD and suggests the integration of new dimensions and technologies in future research. It is recommended to prioritize a change of philosophy and mentality to achieve better results, using Kotter’s method for change management, which will allow leading the transformation processes within the SME in a strategic and effective way.

6. Conclusions

Regarding the first specific objective, the management of residential buildings of an SME and one of its projects was evaluated, identifying nine recurring problems, such as deficiencies in plans, measurements, and budgets, as well as delays due to inadequate planning in the supply of materials. Regarding the second specific objective, eight optimization proposals were developed based on BIM and IPD methodologies. The introduction of NEC4 ECC collaborative clauses to guarantee contractual clarity, Trimble Connect ECD for efficient document management, Revit and Navisworks to facilitate the management of BIM models, Early involvement of the contractor to reduce modifications, and ICE sessions to improve communication, coordination, and collaboration. The 3D model allowed the identification of 0.48 interferences per m². The 4D model facilitated progress monitoring. The 5D model optimized costs by 5.28%, with a return on investment of S/3.94 per sol invested. Regarding the third specific objective, validation using Z-statistical analysis confirmed that the methodology optimizes costs and provides more accurate data. Furthermore, the validation matrix highlighted the NEC4 ECC collaborative contract, early contractor integration, and 3D and 5D models (Revit and Navisworks) as the most effective tools for solving management problems. In conclusion, the general objective was achieved by demonstrating that the IPD and BIM methodologies optimize the design stage in residential buildings, solving management problems, providing precision in deliverables, ensuring contractual clarity, improving planning, and fostering effective collaboration and communication. Its adoption in future projects is recommended for its ability to improve management, contributing to closing the knowledge gap in this field.