Impact of Using an Exchange Model (EM) to Support the Early Assessment Process of Industrialized Timber Projects

Abstract

Standardized information on the processes and requirements for information exchanges is critical to ensure accurate cost estimations. However, traditional methods based on 2D information lack the standardization and information required for efficient and reliable early commercial evaluation. This study aims to evaluate the effectiveness and efficiency of the information exchange model (EM-01) proposed for the commercial evaluation of industrialized timber projects. This study adopted two illustrative cases of projects to make a comparative analysis between the traditional method that prefabrication companies use and the EM-01. The evaluation focused on effectiveness, efficiency, level of certainty, and the user’s perception. The results indicate that both methods enable project evaluation. However, the EM-01 offers better efficiency by reducing work time, reduces uncertainty by minimizing assumptions, and improves the user’s perception of the reliability of the commercial evaluation. The EM-01 provides more standardized information and specific structural design data supporting the early commercial evaluation. This study supports the idea that incorporating standardized information into the processes and requirements for information exchanges enhances the accuracy and reliability of early commercial evaluation in industrialized timber projects.

1. Introduction

Building Information Modeling (BIM) has significantly affected the construction industry over the past decade [1]. Various studies have shown the benefits of applying BIM, such as improvements in design and faster and more effective processes, such as cost estimates, energy simulations, and on-site monitoring of tasks [2,3].

Similarly, implementing the BIM methodology has also had a relevant impact on the industrialized construction sector. With the help of information-rich construction models and the integration of data from different processes, BIM has provided the industry with great potential to promote the industrialization of construction and even improve the performance of modular construction [4].

To achieve a successful BIM implementation, one of the most relevant aspects to consider is the standardization of information flows between the different activities, disciplines, and phases of a process, as well as capturing the correct information within each information model [5]. Standards are fundamental for communication between the various disciplines involved in projects, whether architects, engineers, contractors, specialists, or owners, who work with different nomenclatures, vocabularies, geometries, formats, and data schemas. Therefore, advancing standardization is a key factor in adopting BIM [6].

Likewise, the development of BIM standards makes it possible to address the different interoperability challenges that occur within the workflows of this methodology. Interoperability is the ability of diverse systems, organizations, and/or individuals to work together, using each other’s parts or equipment, to achieve a common goal, regardless of their differences [7]. In this way, when BIM systems are interoperable, the different project participants can share and generate information on the different progress and phases of the project [7].

One of the standards defined within the BIM methodology is the Information Delivery Manual (IDM), which involves the identification and documentation of the processes and requirements for information exchanges within the processes [8]. ISO 29481-1:2016 [9] defines this standard to provide a methodology to capture and specify the processes and information flows required during the asset lifecycle [10]. Likewise, this regulation provides a reliable basis for exchanging information between users so that they can be sure that the information they are receiving is sufficient to carry out the activities within the process [9].

Ramaji and Memari [1] present a method to standardize information exchanges in industrialized modular projects, developing an IDM based on the method proposed in the National BIM Standard (NBIMS-US) and incorporating the Product Architecture Model (PAM) concept, whose purpose is to address the additional needs that exist in the development of modular buildings [1].

On the other hand, Nawari [5] addresses the challenges and opportunities to advance BIM standards in off-site construction. In this research, an IDM is proposed that provides a concrete description of the off-site construction processes of buildings and the information requirements that must be delivered to allow these projects to be carried out successfully. The proposal of this IDM incorporated exchanges of information between various actors involved: architects, engineers, manufacturers, general contractors, and other subcontractors [5].

In order to further advance the harmonization of standards in timber construction and framed in the Finnish project “projectGENERIC” and “Puurakentamisen suunnittelun automaatio”, Keskisalo, M. et al. [11] published a paper whose objective is to map the needs of companies in the object sector with BIM modeling to incorporate them into the BIM object library “Nordic BIM library” and serve as a basis for the harmonization of standards in the construction sector with mass timber.

As part of the project UF-DCP-002 Wood Structural Design to Structural Analysis [12], an IDM and Model View Definition (MVD) standard for the design of timber structures is proposed. N. Nawari [6] reviews the state of BIM tools in modeling timber structures and formulates the functional requirements for developing successful BIM models to design timber structures. In particular, this research focused on the exchanges of information between architects and engineers during the preliminary design phase of the project [6].

According to this research, it is possible to mention that the development and advances in BIM standardization within the off-site timber construction industry have been addressed and explored independently. On the one hand, it has focused on developing the projects themselves, and on the other, requirements and process mappings for off-site construction have been formulated. There is a need for the integration of both processes.

To unite both aspects, Rojas et al. [13] analyze the IFC defined in the international standard ISO 16739-1:2018 [14], which, although it is replaced by ISO 16739-1:2024 [15], does not imply any change in the IFC object of said work, referring to building projects, having produced changes only in the inclusion of aspects related to linear and civil works. Rojas et al. [13] propose a new exchange model in which a series of parameters are incorporated that are considered minimum to achieve optimal implementation of the BIM methodology in industrialized construction projects with a timber frame structure.

In this way, having a standardized data model that considers the information requirements for each activity is essential to ensure that information exchanges are carried out better, and with it, the process and development of projects improve themselves. Thus, in the context of adopting the BIM methodology within industrialized timber projects, one of the important challenges is to define the exchanges of information between the different processes, one of these being the commercial evaluation process that occurs in the early stages.

Cost estimation in the early stages is a crucial element in any construction project. An accurate estimate of the initial cost will support project decision-making, considering that the project cost is significantly affected by decisions made in the design phase [16]. In this way, the commercial evaluation process in the early stages takes on great significance, particularly for industrialized timber projects. This process must consider not only the requirements of a traditional project but also the assumptions and requirements that the design entails, which are necessary for the industrialization, manufacturing, and assembly process.

Regarding the use of BIM in the timber industry and, in general, in the construction industry, it has been based on the use of digital models that have made it possible to facilitate the different processes and activities within the development of projects, since through the use of information models, it has been possible to coordinate the different specialties, improve the visualization of its components, analyze performance, and facilitate the processes of cost estimates, assembly sequence, manufacturing, logistics, and others [17,18].

The timber industry has made progress in defining BIM standards, covering the required information exchanges, for example, for the design of timber structures, focusing on information exchanges between architects and engineers during the preliminary design phase of the project [6]. Similarly, Rojas et al. [13] proposed an IDM associated with the evaluation process of industrialized timber projects for the system based on light frame (2D) panels. This proposal identifies the phases, actors, and activities present within this process, where the approach was based on the exchange model (EM) required to evaluate the project during the early phases. The EM defines the functional content of the information to be exchanged in a use case. A use case defines the data required in each information exchange scenario between disciplines within a workflow.

Along these lines, it is possible to mention that, although there have been developments of standards that have sought to map the standardization of information flows between processes, the real impact of using these standards and thus valuing the effects and possible improvements (for example, increased efficiency) in the development of activities that are executed during the different phases of the project has not been evaluated.

In this way, this research aims to evaluate the effectiveness and efficiency of the information exchange model (EM-01) proposed for the commercial evaluation of industrialized timber projects. The evaluation process was carried out based on two projects (“case illustrations”) where two experienced professionals from different industrialized timber companies implemented the information exchange model (EM) developed by Rojas et al. [13] and compared their results with a traditional method that used information based on planimetry, documents, or 2D information.

This study contributes practical insights about incorporating standardized information into the processes and requirements for information exchanges to enhance the accuracy and reliability of early commercial evaluation in industrialized timber projects.

2. Methodology (Experimental Design)

The research is developed by studying two illustrative cases of projects with similar characteristics in terms of volumetry and use, and both were designed with the construction typology object of this research: the structure of light timber frame panels. The analysis method used for both cases to meet the objectives set is described in detail below.

2.1. Objective and Description of the Experiment

The objective of the experiment is to evaluate the impact of using an information exchange model to support the early evaluation process of prefabricated timber projects. To this end, the evaluation of the data exchange (MA) model proposed in the IDM of Rojas et al. [13] is carried out, specifically, the one defined as EM_01, specifically designed for early assessment. This exchange model requires information (Exchange requirements, ERs) related to the conceptual evaluation of the model. The data exchanged refer to the project’s general architectural and geometric characteristics, such as volumes, construction systems, and cost estimates per square meter of panel. To do this, the model proposes a series of minimum parameters, geometric and non-geometric parameters. This proposal incorporates new non-geometric parameters concerning the provisions of the international standard ISO 16739-1:2018 [14]: IFC (parameters that have not been modified by ISO 16739-1:2024 [15]) to complete this standard and thus be able to carry out a more accurate early assessment through the use of BIM methodology.

In order to test the effectiveness and efficiency of the proposed model EM_01 by Rojas et al. [13], and therefore considering these new parameters, this paper compares the results obtained concerning those derived from the application of the traditional method used by prefabrication companies in the early evaluation of their projects and those obtained by applying the EM_01 exchange model.

The experiment is divided into 2 phases (

Table 1. Research methodology for the evaluation of the EM_01 model.

Phase	Activities	Method
Phase 1	Company A evaluates Project W using the information exchange model (method X) Company B evaluates Project W using the traditional method (method Y)	Charrette
Phase 2	Company A evaluates Project Z using the traditional method (method Y) Company B evaluates Project Z using the information exchange model (method X)

). The first phase consists of two companies evaluating the W project. Company A uses the EM_01 exchange model in this phase, while Company B uses the traditional method (method Y). Then, in Phase 2, Project Z is evaluated, in which Company A uses the traditional method (method Y) and Company B uses the exchange model (method X) to perform the evaluation. This way, there is no bias between the methods since different projects are evaluated using the two possible methodologies.

The method used is based on a charrette for the two activities within each phase of the experiment to minimize biases about how participants perceive and interpret the information contained in the BIM exchange model. Research charrettes are an effective method of gaining industry input and insight in studies focused on determining best practices or understanding key parameters affecting project performance by tapping the extensive expertise of volunteers.

The charrettes were formed by the evaluators of the companies participating in the experiment. This charrette is based on carrying out the evaluation process (quote) of each project. At the same time, the evaluator answers a questionnaire in which different questions are asked about obtaining the metrics of each variable that is tested in this experiment.

2.2. Experiment Variables

2.2.1. Independent Variables

The experimental design described above mainly involves two independent variables described and detailed in

Table 2. Description of independent variables.

Independent Variables	Description	Types
Projects	This variable represents the geometric and non-geometric characteristics and the project information. Each project has a defined architecture and different information parameters (non-graphic information) that are specific to each project and impact the design. The non-geometric parameters are thermal regulations, region, commune, type of soil, seismic zone, type of grouping, number of floors, and height of walls.	Project W	Architecture of a four-story residential building.
		Project Z	Architecture of a four-story residential building.
Evaluation methods	This variable involves the types of methods that are used to evaluate projects.	Method X: Exchange model	This method uses the exchange model, which contains different information parameters, to carry out the early evaluation of the project.
		Y-Method: Traditional	This method mainly uses information based on planimetry, documents, or 2D information for users to evaluate the project.

.

2.2.2. Dependent Measured Variables to Assess the Impact of Using the EM_01 Model

In order to test and compare the result of the early evaluation of the projects using both the exchange model and the traditional method, the purpose of this contrast is based on the measurement of different variables to evaluate whether the use of the data model (method X) generates benefits in the early evaluation process compared with the traditional method (method Y). To this end, during both phases of the experiment, the measurement of the metric variables associated with the different dependent variables of the experiment expressed in

Table 3. Description of dependent variables.

Variable	Description	Testing
Effectiveness	Feasibility of carrying out the project evaluation process with the information provided in the EM_01 exchange model	Achievement of performing the assessment
Overall Assessment	General perceptions about the advantages and challenges of the methods.	Opinion of the evaluators regarding the use of both methods.
Efficiency	Level of resources needed to carry out the project evaluation.	Actual working time + client response times Number of interactions required with the client
Level of certainty	Quantitative and qualitative evaluation of the level of certainty of each company at the time of carrying out the evaluation process	Number of assumptions made during the evaluation Perception of the evaluator according to scale

will be carried out:

Based on these variables, a questionnaire was created that was applied in illustrative cases after the evaluation of the projects with the methods. The questionnaire was structured to conduct a guided interview with the users and collect information on the performance of each project according to the model applied.

3. Independent Variable Specifications

3.1. Projects to Be Evaluated (Illustrative Cases)

Before testing the exchange model, it is important to mention that this model is generated through a digital platform, which was developed and implemented based on the information exchange proposal present in the IDM of Rojas et al. [13]. This work was carried out with an interdisciplinary research team, which worked on this platform to obtain the project’s schematic design. For this experiment, the information associated with the W and Z projects was entered into the platform, resulting in the exchange model being tested in this work.

Table 4. Project background (illustrative cases).

	Project W	Project Z
Architectural Plan
Thermal regulation	Current thermal regulations	Current thermal regulations
Region	Santiago Metropolitan	Santiago Metropolitan
Municipality	Santiago	Ñuñoa
Soil Type	B	B
Seismic Zone	2	2
Grouping Type	Collective building	Collective building
Number of stories	4	4
First floor	Grit	Grit
Wall height	2.4 m	2.4 m

shows the background details of both projects.

Illustrative cases presented have been chosen because of the following considerations: these two projects can be considered as representative examples of current timber frame building construction. In addition, volumetry and partitioning are similar in both projects, which allows exchange companies and methods to carry out the two phases of this experiment (Table 1). Finally, the expected quotations for the two cases are significant enough to avoid wrong deviations due to small differences in design.

3.2. Evaluation Methods

3.2.1. Model Exchange Method EM_01 (X)

The exchange model has different entities and parameters that allow the user to get relevant information to support the project evaluation process in the early stages.

This exchange model defines parameters based on a minimum series of attributes that must be considered in this process. These parameters are classified as geometric and non-geometric. The geometric parameters refer to the dimensions of the panels that make up the volumetry of the project, mainly walls and floors (length, height, and thickness of panels), and their location concerning the floor level on which they are located. As non-geometric, the model defines a series of relevant parameters due to the impact that the different variables applied to them have on the project’s final cost. These parameters refer to the construction solutions adopted in which the materials that make up the panels and their configuration are defined, which allows the costs of materials and manufacturing processes to be evaluated more precisely. Within the non-geometric parameters, aspects are also defined that allow for calculating production times and availability in the market of the materials that make up the panels and the means necessary for their manufacture.

Table 5. EM-01 exchange model parameters.

Parameter Type	Parameters	Description
Geometric	Length	Minimal geometric definition: prior knowledge of this parameter allows the optimization of production and logistics from transport to the site.
	Thickness
	Height
	Level	The location of the panels by levels provides important information to establish in an orderly manner the supply and designation of storage areas for each of the elements that make up the structure.
Non-geometric	Identification of the panel construction solution	The definition of the construction typology allows us to know the materials that will be used in the manufacture of the panels and to estimate the costs and their availability in the market.
	Weight	It allows the design of a logistics plan for the transfer of panels on site, establishing the necessary auxiliary means of lifting and moving to the plant.
	Specification of the type of anchors	The cost of fasteners is significant, so this parameter is relevant to increasing accuracy in early cost estimation.
	Cost per square meter of panel	It allows quantifying the direct costs of the project. Applying variations to the parameter also allows for obtaining and comparing total costs for the different variables.
	Panel Type Identification	It allows for the identification and quantification of the panels that make up the project and a more orderly management.
	Identifying the type of table that makes up the panel	The type of board and the configuration of the assemblies allow the plan of the production times and costs of the panels, facilitating the estimate of the impact on the total cost more accurately.

presents the geometric and non-geometric parameters with a strong description of the relevance of their consideration in the exchange model for improving accuracy in early assessment. The parameters listed in the table include the minimum information necessary to apply the exchange model proposed and tested in this study.

In order to be able to carry out the commercial evaluation process in the early stages using the method based on the EM_01 exchange model, the information provided to the evaluators of companies A and B (in Phases 1 and 2) under this method is described in

Table 6. Inputs and deliverables in evaluation method X (EM-01).

Input or Deliverable	Description
1. Summary sheet with background of the project and scope of the evaluation	The document that contains the non-geometric information associated with each project and the scope of the evaluation.
2. Volumetric 3D model of the project	The digital model in IFC and RVT format that has the entities of walls (vertical panels), mezzanines, and ceilings (horizontal panels) of each project. Each entity has different information parameters that facilitate the early assessment process.
3. Technical sheets of construction solutions	The document that shows information associated with the composition and acoustic, fire, and thermal performance of the construction solutions proposed for the components of the project (walls and floors).
4. Tables with information parameters	The summary table contains each entity’s information parameters (wall, mezzanine, ceiling) present in the 3D model. These tables are obtained directly from the 3D model through an export process because they are parametric information contained in the entities of the 3D model. In addition, a brief description and explanation of the meaning of each parameter is provided.
5. Table with unit costs of materials	The table contains the approximate unit costs (in UF/m2) of the materials in light timber framing construction solutions (cladding, insulation, and wood).

.

According to what is specified in Table 5, the entities present in deliverable 2 (volumetric 3D model) associated with the wall, mezzanine, and ceiling panels have different parameters that allow the evaluator to provide relevant information to support the project evaluation process in the early stages.

In addition to geometric information, each entity within the model contains either instance or type parametric information that complements the model data.

On the one hand, instance parameters are unique to a particular element, i.e., unique values that belong to the element. On the other hand, type parameters apply to more than one element and are specific to the solution family.

Table 7. Wall entity information parameters.

Entity Wall	Type Parameters	Description
	Fire resistance	Indicates the fire resistance property of the wall
	Core wood species	Indicates the species of wood in the core of the wall (studs and plates)
	Thermal transmittance	Indicates the thermal performance of the wall
	Thermal transmittance	Indicates the acoustic performance of the solution
	Wet room use	Indicates whether the wall solution can be used in wet rooms
	Solution code	Enter a code to identify the solution
	Studs spacing [mm]	Indicates the distance of the studs inside the wall.
	Studs dimensions [mm]	Indicates the dimensions of the dimension of the studs
	Función de la solución	It indicates the function of the wall, whether it is perimeter, interior, or dividing
	Linear weight [kg/m]	Indicates the weight per unit length of the solution
	Construction system	Indicates the construction system in which the solution is used
	Instance parameters	Description
	Id construction panel	Panel identifier or label
	Manufacturing table number	Number that identifies the table on which the panel will be built
	Storey	Indicates the floor on which the panel is located
	Anchor specification	Corresponds to the specification of the anchorage obtained by each structural segment
	Anchor position	Corresponds to the position where there are anchors within a panel, according to the structural segment belonging to the panel, in local coordinates
	Number of end studs	Number that indicates the number of edge studs that the structural segments will have within each panel
	Inner nailing pattern of lateral structural segments	Corresponds to the information on the nailing patterns of the structural plates (on their perimeter and inside)
	Perimeter nailing pattern of lateral structural segments
	Internal nailing pattern of gravitational structural segments
	Perimeter nailing pattern of gravitational structural segments
	Structural grade	Corresponds to the structural grade of the panel core
	Start–end position structural segment	(Local) coordinates that indicate where a structural segment begins and ends within the panel.

and

Table 8. Slab entity information parameters.

Slab Entity	Type Parameters	Description
	Core species	Indicates the species of wood in the core of the slab (beams)
	Acoustic resistance	Indicates the acoustic performance of the solution
	Fire resistance	Indicates the fire resistance property of the wall
	Thermal transmittance	Indicates the thermal performance of the wall
	Weight per square meter [kg/m2]	Indicates the weight per unit area of the solution
	Construction system	Indicates the construction system in which the solution is used
	Wet Room Use	Indicates whether the wall solution can be used in wet rooms
	Solution Code	Enter a code to identify the solution
	Beam Spacing [mm]	Indicates the distance of the beams to the inside of the slab
	Beam dimension [mm]	Indicates the dimensions of the beam dimension
	Function of the solution	Indicates the function of the slab (or mezzanine)
	Normalized impact sound pressure level [dB]	Indicates the sound insulation information of the solution
	Instance parameters	Description
	ID construction panel	Panel identifier or label
	Assembly table number	Number that identifies the table on which the panel will be built
	Storey	Indicates the story on which the panel is located
	Structural grade wood	Corresponds to the structural grade of the panel core

show the entities present in the model and their information parameters.

Likewise, the composition of each wall or slab solution is also stored in the type information, where the materials of each element cladding are identified (Figure 1).

In order to comply with standardized information flows, the exchange models to be tested are delivered to users in IFC format because pre-fabricators can use different software for their tasks and processes. In this way, the exchange model is delivered in an open-source format, such as the IFC data model standard proposed by Building Smart [19].

On the other hand, the information parameters in each entity presented in the previous section are contained within a specific property set that separates the instance and type parameters for each entity, whether a wall or a slab. Figure 2 and Figure 3 show the interchange models corresponding to projects W and Z, with the information parameters contained in the property sets.

3.2.2. Traditional Method (Y)

Table 9. Inputs and deliverables used in the evaluation method Y (traditional).

Inputs or Deliverables	Description
1. Summary sheet with background information on the project	Document containing the non-geometric information associated with each project.
2. Two-dimensional planimetry	Plans (cuts and elevations) in PDF and dwg format associated with the architecture of each project
3. Table with unit costs of materials	The table contains the approximate unit costs (in UF/m2) of the materials in light timber framing construction solutions (cladding, insulation, etc.).

presents the inputs and deliverables provided in the traditional method (Y) for the early evaluation process.

4. Results of the Evaluation of the Use of the EM_01 Exchange Model in the Early Evaluation Process of Industrialized Timber Projects

This section presents the results of the experimental method described in Section 3. The results are shown for the tested variables associated with the effectiveness, general evaluation, efficiency, and level of uncertainty of the users when carrying out the commercial evaluation process of a timber building project when using the traditional method (based on 2D information) and, on the other hand, when using the EM-01 information exchange model.

The results are based on the charrettes in which the evaluators of the participating companies participated at the time of carrying out the commercial evaluation process of the W and/or Z project. The graphs and conclusions presented below are obtained directly from these questionnaires.

4.1. Effectiveness and Overall Evaluation

First, the results show that it is possible to conduct the project’s commercial evaluation using either of the two methods. Considering that the traditional method is effective since it is the method that is commonly used and is validated by experience, and that quotations obtained are relatively similar by using both methods, this implies that with the exchange model method, obtaining the value of a quote for the project in question is possible, demonstrating its effectiveness. Figure 4 shows the values obtained by both methods for projects W and Z.

According to the evaluators’ opinions, although the commercial evaluation process was possible using any of the methods, the exchange model (method X) has certain advantages over the use of the traditional method. According to the evaluators, one of the main advantages of using the EM_01 model is that there is accurate information to ensure minimum values required for the evaluation, for example, square meters of solutions, type of solutions, acoustic and fire requirements, and number of right feet. Likewise, another advantage of this method is that it allows for greater speed in carrying out the calculations (for example, obtaining the total square meters of the building), where subsequent verification is also not required. Similarly, the EM_01 model allows for more specific and detailed data regarding information associated with manufacturing, for example, the number of panels and configuration of assembly tables, which allows for a better estimation of the project’s manufacturing times and costs.

On the other hand, the evaluators also commented on possible difficulties or disadvantages regarding using this model in contrast to the traditional method. These disadvantages are mainly based on the need for and use of more specific programs (software or applications), where an evaluator may not be familiar with these tools. Also, there is no room for iterations when using the exchange model, and comparing it with projects already executed is not easy. Finally, another disadvantage is that it would be very difficult to detect if the exchange model has an error.

According to Figure 4, the quotation results obtained using the exchange model method are higher than the traditional method for both projects. Although the difference does not exceed 5% in any of the projects, according to users, this is mainly because the exchange model considers a more conservative structural result than the one considered in the traditional method.

4.2. Efficiency

Figure 5 shows the result associated with users’ (actual) work time to evaluate the projects.

The results show that work times are approximately 40% shorter when using the information exchange model than when using the traditional method.

Regarding the response times of the client associated with queries made by the evaluator, in the case of user A, a query was made before the experiment’s start, associated with the evaluation’s scope. For this, the client’s response time was 1 day. Likewise, user B did not consult the client during the evaluation.

Table 10. Number of interactions required with the client during the evaluation.

	Traditional Method (Y)	Exchange Model Method (X)
Project W	0	1
Project Z	1	0

shows the number of interactions made with the project client.

4.3. Level of Certainty

Finally, the evaluation process using both methods was tested concerning the user’s uncertainty level, according to their perception during the process. For this, as a quantitative variable of this aspect, the number of assumptions made during the evaluation was counted (Figure 6).

According to these results, the quantitative analysis found that the exchange model for the evaluation process in both projects requires fewer assumptions than the traditional method.

To have a qualitative result of the level of uncertainty, users delivered their perception during the evaluation process by using either the traditional method (Y) or the exchange model (X). Figure 7 introduces the perception scale.

Table 11. Result of the user’s level of certainty (evaluator’s perception).

	Traditional Method (Y)	Exchange Model Method (X)
Project W	Safe	Very Safe
Project Z	Safe	Very Safe

shows the result associated with the user’s perception when carrying out the project’s commercial evaluation process using both methods. According to the users’ appreciation of the exchange model method, commercial evaluation is safer than traditional methods. Therefore, this result can be used directly as a budget for the preliminary project.

5. Discussion

To validate the EM_01 information model proposed by Rojas et al. [13] for commercial evaluation in the early stages of industrialized timber projects, the effectiveness, efficiency, and level of uncertainty were measured, and its performance was compared with the traditional method.

First, the effectiveness results show that it is possible to conduct a commercial evaluation (or quote) of the project with both methods. However, the value of the quote obtained using method X (exchange model) turns out to be 1.5% higher in Project W and 4.9% higher in Project Z, compared with the quote obtained using the traditional method (method Y).

According to users, this is mainly because the exchange model provides more detailed information regarding the building design compared with the traditional method. More information reduces uncertainty in decision-making and, therefore, helps to have a more realistic approximation of the project’s cost in the early stages. In addition, users stated that in the exchange model, the results of structural verification are more conservative than those considered in the traditional method. For example, in the traditional method, a smaller spacing of straight feet and beams is considered, and also a smaller number of structural walls, and therefore fewer anchors, resulting in a lower commercial evaluation based on this method than the exchange model.

On the other hand, the exchange method evaluation process was more efficient than the traditional method, resulting in less work time to make the project quote. According to users, this occurs because identifying certain parameters and variables required to make the quote is very quick to identify and obtain based on a 3D model versus using planimetry in the traditional method. In fact, users stated that many times, the development of a 3D model to deliver a quote is necessary to obtain values of the most accurate variables (for example, square meters of solution, openings) and to be able to iterate more quickly and efficiently with the client.

Regarding the interactions required with the client, the exchange model registered an interaction associated with the scope of the evaluation. In the traditional model, the client did not require any interaction. Based on these results and user reviews, the number of interactions with the client would not be related to the evaluation method used to carry out this process. However, instead, they are associated with the evaluation’s scope definitions and contractual issues, i.e., items to be executed and considerations within the evaluation (assembly, manufacturing).

Finally, the level of uncertainty was tested quantitatively and qualitatively. The quantitative analysis found that when using the exchange model, the number of assumptions made is lower than when the traditional method is used. According to users, the exchange model contains more information and, specifically, the structural design of the building compared with the traditional method. For example, the number of studs and their spacing, the number of panels and their configuration on manufacturing tables, and m² per type of solution. This has an impact on fewer assumptions during the evaluation process. Another user said it was unnecessary to assume the number of structural walls per axis, the spacing of studs in vertical panels, or the spacing of beams in mezzanines.

The qualitative analysis showed that using the exchange model makes the evaluator perceive a safer and more reliable process. In both cases, this result could be used directly as a budget for the project in the early stages. One of the users commented that using the exchange model gives a “greater ease of calculating parameters that are considered within the evaluation, which makes the process more secure.” Likewise, the user stated that nowadays, the information that is sent to make the quote of a project in the pre-design stages is very vague (from a hand drawing, unclosed planimetry, etc.), which, in the same way, sometimes forces the evaluating users to develop BIM models or 3D models to be able to better visualize the definitions and conditions of the project and, in the face of possible changes, iterate more securely with the client.

6. Conclusions

This research shows the impact of using an information exchange model to carry out the commercial evaluation process in the early stages of an industrialized timber building project. For this, two illustrative cases were applied based on two projects (Project W and Z) where the evaluation process was carried out using the traditional method, based on 2D information (planimetry), and using the method based on the information exchange model, which was proposed in the research of Rojas et al. [13], which considers various information parameters associated with the building’s construction solutions.

The results of the illustrative cases show that using a standardized information exchange model to conduct a project’s evaluation process allows for increased efficiency of the process in question, mainly reducing work times. It also reduces the uncertainty of the process by having fewer assumptions and working with an information model that allows iterations or changes (if any) to be made more easily and safely. Similarly, according to users’ perceptions, using the exchange model makes obtaining a more secure quote result possible, which can be used directly as a preliminary project budget.

The study presented in this document was limited to the commercial evaluation process of industrialized timber projects, using as a basis the proposal of the Information Delivery Manual (IDM) presented in the work of Rojas et al. [13]. It is proposed as future work to extend the illustrative cases presented in this case study to other sub-processes or tasks within the process of industrialization of timber projects and thus identify not only a standardized data model that contains the information requirements for the different tasks but also evaluate the impact that this has on the different tasks, being able to improve and make more efficient the sub-processes within the value chain of this type of project. It is also proposed that this EM be evaluated for the early identification of risks. Finally, it is also recommended that this exchange model be studied to determine how it could be adapted and if it is effective in the case of other wooden structures.