Customer interactive building information modeling for apartment unit design

Automation in Construction 35 (2013) 424–430

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Automation in Construction journal homepage: www.elsevier.com/locate/autcon

Customer interactive building information modeling for apartment unit design Soyeon Lee, Mikyoung Ha ⁎ Department of Interior Architecture and Built Environment, Yonsei University, Republic of Korea

a r t i c l e

i n f o

Article history: Accepted 28 May 2013 Available online 21 June 2013 Keywords: Building information modeling Customer needs Parametric design Apartment unit

a b s t r a c t Although apartment houses are efficient buildings in an urban society, they have a drawback in that the design of a unit is so monotonous that it cannot meet various customer needs. To provide customers with individually tailored unit designs, this study proposes customer interactive building information modeling (CIBIM), a type of parametric unit design method. In CIBIM, a parametric 3D modeling tool has been used to create separate fixed walls and movable walls which were linked to lighting and furniture families.

Customer satisfaction with CIBIM was evaluated through a survey comparing an actual model house and a new design. The efficiency was evaluated by comparing a number of drawings using conventional methods and CIBIM. In comparison, the results show that the CIBIM provides various designs which reflected individual desire to change. CIBIM represents a means to meet customer needs as well as a way to reduce labor requirements by designers. © 2013 Elsevier B.V. All rights reserved.

1. Introduction Apartment houses which accommodate many people within a spatially limited area are efficient buildings in an urban society. Especially in Korea, among all types of housing, apartments accounted for the highest proportion, at 59.0%, as of 2010 [1]. Therefore, as a type, apartment houses are one of the most important products in the architecture, engineering, and construction (AEC), and facilities management (FM) market. However, apartment houses have disadvantages in that the designs of unit plans are monotonous such that they are unable to meet various customer needs [7,13]. Therefore, there are many people who undertake the remodeling of their apartment unit despite the fact that it may be newly built [4,12]. This represents not only a waste of funds but also generates unnecessary emissions of environmental waste and pollution.

Furthermore, although family types change continuously, designers and engineers could not reflect such changes [7,17]. In 1985, four-member families, the most common type, numbered 2,421,627 (25.3%), whereas in 2010, two-member families were most common, at 4,205,052 (24.3%). It is projected that by 2035, one-member families will be most common, at 7,628,065 (34.3%) [1]. Unit designs should reflect this trend. In addition, the apartment market is faced with a competitive environment due to the over saturation. In 2008, the supply of housing ⁎ Corresponding author at: Department of Interior Architecture and Built Environment, Yonsei University, 417 Samsung Hall 134 Sinchon-Dong, Seodaemun-Gu, Seoul, 120-749, Republic of Korea. Tel.: +82 2 2123 3135; fax: +82 2 2123 8662.

E-mail address: mkha@yonsei.ac.kr (M. Ha).

0926-5805/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.autcon.2013.05.026

per family was 100.7%, and the rate is becoming gradually higher [1].

Therefore, in such circumstances, the housing market must change from a supplier-oriented to a customer-oriented market [18,21]. Moreover, architectural designers should begin to actively accept the variously changing needs of customers.

However, traditional 2D drawings are limited to the generation of separate drawings such as floor planes, elevations, sections, and details of a building. Therefore, if the design is modified, all of the drawings should be modified individually, which is exhaustive in terms of time and labor, resulting in numerous errors [10]. Furthermore, traditional 3D models are also used for only graphic visualization. They do not provide any information about design analysis and data integration, lacking in consistency within the projects [3]. For these reasons, variation of the design in apartment units with hundreds or thousands of units in a project is hesitantly accepted, not only by designers but also by owners, managers, and engineers.

To resolve these problems with the traditional process, “Building Information Modeling (BIM)”, based on parametric designs, has been designed. In a BIM environment, accurate and consistent 2D drawings and 3D models can be extracted for any specified view of a project. This principle reduces the time, labor, and errors associated with generating drawings and models [9,19]. Therefore, when modifications of the design are required, consistent drawings and models which operate parametrically can be generated as soon as the design is changed. In addition, in a parametric design, instead of drawing each building element, such as a wall, window or the furniture separately, a designer defines a model family which varies according to their context [3]. Therefore, using a parametric design in apartment units can be an innovative solution for a designer

S. Lee, M. Ha / Automation in Construction 35 (2013) 424–430

who seeks to diversify the monotonous unit. It can lead to the creation of more various unit designs which satisfactorily reflect the individuality of each customer with high quality in a more efficient manner.

Furthermore, to express the designer's reflection of customer needs, the concept of “Interactive” is stressed in this paper. Recently, due to the development of ubiquitous technology, interactive architecture plays an increasingly important role in urban society [15]. Interactive architecture emphasizes information exchanges including conversations [11], and expresses an appropriate representation to those who seek to resolve the disconnection between customers and designers. Therefore, based on parametric methodology and interactive architecture, “Customer Interactive Building Information Modeling (CIBIM)” is proposed in this paper to improve the communication between customers and designers.

2. Material and methods

The CIBIM system proposed in this study was tested at an actual construction site to verify its feasibility. The case is an apartment housing project which is on sale at a model house, scheduled to be completed in June of 2014. The project is appropriate as a case study because it contains a large total number of 2603 units. In this paper, the 84 m2F type, which accounts for 300 units out of the total of 2603 units, was selected as the case study unit. The major features of the project are summarized in Table 1.

2.2. Application of the CIBIM in unit design There are several effective BIM authorizing tools on the market, including Revit from Autodesk, Bentley Architecture from Bentley, ArchiCAD from Graphisoft, and Digital Project from Gehry Technologies.

In this study, although other similar digital applications could be used, Autodesk Revit Architecture, a universal and user-friendly program for parametric design [3,14] is used to apply the CIBIM. The process to make a parametric unit design system of CIBIM using the Autodesk Revit Architecture program is as follows (Fig. 1): • Step 1: generate immobile walls. The outer wall and structural wall were locked.

• Step 2: generate mobile walls. These walls are not locked so that the customers can move or remove them as they want. For example, if a customer increases the distance between two walls by 200 mm, the locked wall does not move while only the unlocked wall moves 200 mm. Create the door and window families and locate them in the wall. In the parametric design, designers use a model family, Table 1 Major features of the case project.

Major features Hwagok-dong, Gangseo-gu, Seoul, Korea Residential building 2014. 6

Usage Estimated completion time Design Area of site parameters Floor area ratio Number of stories

which is a set of relationships that vary according to their context.

Families are defined using parameters which involve distances and rules such as “attached to,” “distance from,” and “same interval.” These relationships allow the families to be verified according to their contextual relationships [3]. In addition, create the floor and attach it to the wall.

• Step 3: calculate the area of each room. The guide lines of the area are attached to the given walls so that they can be changed parametrically when the walls are replaced.

• Step 4: create the ceiling and place the lightings on the ceiling. Link the lighting locations to the walls so that they move parametrically with the walls.

• Step 5: create the furniture families and locate them in the appropriate place of the unit. Because the furniture families are defined by the above-mentioned family rules, they can also be modified parametrically when the unit design is changed.

The process using CIBIM is as follows:

2.1. Major features of case project

Address

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132,026 m2

258.6% 3 floors underground–21 floors above ground Number of apartments 37 Area of apartments 59 m2, 84 m2A, 84 m2B, 84 m2C, 84 m2D, 84 m2E, 84 m2F, 119 m2, 128 m2A, 128 m2B, 128 m2C, 128 m2D, 128 m2E, 152 m2 Number of households 2603

• Step 1: the participants see the 84 m2 F-type model house.

• Step 2: they learn how to use the interface of CIBIM briefly.

• Step 3: they move and remove the walls and furniture of the unit.

They can communicate with designers who consult with them about the unit design and assist with the use of the program. The participants can view 3D images at any view of their new design and can alter the design as they please immediately.

2.3. Customer satisfaction survey of CIBIM The CIBIM was evaluated by customers who visited the model house of the case project. They could compare the model house unit design and the modified CIBIM design. In the first step, new apartment unit designs using the CIBIM program were conducted. In this step, participants could communicate with architectural designers who could facilitate a unit design which is appropriate for each participant. Because the design in the parametric modeler automatically adjusts to changes by users [3], customers can reflect their requirements in their new unit design through the exchange of ideas with the designers. In the second step, a questionnaire survey was conducted to compare the different levels of customer experience satisfaction when they viewed the model house and new unit

by CIBIM. Ninety eight of the participants responded to the questionnaire survey. Age, gender, cohabiting family number, and computer experience were collected as the general information. Computer experience was evaluated by referring to a previous study measured on a sevenpoint scale (1 representing no computer use and 7 representing persons who were involved in developing computer software) [23]. In order to evaluate the CIBIM result, the questionnaires focused on three areas: serviceability, design improvement, and availability. To extract the evaluation criteria for “serviceability” and “availability,” this paper referred to questionnaires which were used to study the satisfaction of users after using a newly proposed system [6]. The “design improvements” were evaluated through a reference to the semantic environmental (SMB) scale developed by Küller [5]. The purpose of the SMB scale is to systematically evaluate an environment which a customer perceives. Although the SMB scale has mostly been suggested for use in real environments, Küller noted that it could also be used for environments shown with sketches and 3D models. For this reason, the SMB scale was chosen to evaluate the environments of the CIBIM models. Each question was rated on a seven-point Likert-type scale (Table 2).

2.4. Comparison of the work efficiency of conventional CAD and CIBIM environment To compare the conventional CAD drawings and parametric CIBIM system objectively, this paper proposed counting the expected number of drawings to modify when the design is changed. The number of drawings represents numerically the labor, time and costs required

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Fig. 1. Process of CIBIM design in an apartment unit.

Table 2 Customer satisfaction survey questionnaire.

Questionnaires Serviceability of CIBIM

Se1: Does the CIBIM process make it easy to understand the apartment unit?

Se2: Is the user interface of CIBIM easy and convenient to use?

Se3: Do you think the communication with designers within CIBIM environment is more effective compared to the conventional process?

Design improvement through CIBIM

Availability of CIBIM

Compared to the design of the model house, new design by CIBIM has more

De1: pleasantness De2: complexity De3: unity

The environmental quality of being pleasant, beautiful and secure.

The degree of variation or, more specifically, intensity, contrast and abundance.

How well all the various parts of the environment fit together into a coherent and functional whole.

De4: enclosedness A sense of spatial enclosure and demarcation De5: potency An expression of power in the environment and its various parts.

De6: social status An evaluation of the built environment in socioeconomic terms, but also in terms of maintenance.

De7: affection The quality of recognition, giving rise to a sense of familiarity, often related to the age of the environment.

De8: originality The unusual and surprising in the environment.

De9: Do you think the overall quality of your final unit design is significantly improved by the use of CIBIM? Av1: Is the utilization of CIBIM in apartment unit design applicable enough?

Av2: Do you think the data accumulated by CIBIM can be effectively used as a valuable reference in the design stage of future similar housing projects?

Av3: Do you think CIBIM and its process can be extended to other types of architectural buildings?

Av4: Do you think CIBIM can serve as a supporting tool for raising corporate images in industry?

Av5: Are you willing to change an existing unit design to the new one modified by CIBIM?

Seven-step scale with 1: strongly disagree and 7: strongly agree.

3. Results

spend most of the time. In addition, a guest room was proposed.

The family with four members wanted to switch the location of the master bedroom and the children's room. The entrance hall was increased for the storage of bicycles and other exercise equipment (Fig. 2).

3.1. Apartment unit design cases of CIBIM

3.2. Customer satisfaction of CIBIM design

In the results of CIBIM design, there were various types of unit designs, as each participant wanted an apartment unit design which was appropriate for his/her family lifestyle. Among them, three representative unit designs were presented in this paper owing to space limitations. In terms of cohabiting family members, the order of the frequency was 4 at 36 (36.7%), 2 at 23 (23.5%), and 1 at 19 (19.4%) (Table 3). Therefore, the drawings of the three family types were presented as typical examples. For the family with one member, the respondent wanted to remove an unnecessary bathroom and two other rooms and increase the size of the living room so that it could be a home office. As the respondent did not often cook at home, she wanted to decrease the kitchen and move it from the southward to the northward area of the unit. The family with two members, an elderly couple in this case, wanted to remove a room and increase the sizes of the master bedroom and living room, where they would

3.2.1. General features of the survey participants The respondents' ages ranged from 29 to 71 years, with an average of 42.92 years (S.D. = 12.16, median = 37). The average number of cohabiting families was 2.83 (S.D. = 1.24, median = 3) and the

for designers. Conventional CAD drawings were obtained from the actual construction company drawings which were used to build the model house.

Table 3 General features of the survey participants.

Mean Ag: Age Ce: Computer experience Cf: Cohabiting families Cf: Cohabiting families (frequency) Ge: Gender (frequency)

S.D.

42.92 12.16 4.20 1.76 2.83 1.24 1 = 19 (19.4%), 2 = 23 (23.5%), 3 = 16 (16.3%), 4 = 36 (36.7%), 5 = 4 (4.1%) M = 39 (39.8%), F = 59 (60.2%)

S. Lee, M. Ha / Automation in Construction 35 (2013) 424–430

order of the frequency was 4 at 36 (36.7%), 2 at 23 (23.5%), 1 at 19 (19.4%), and 5 at 4 (4.1%). The average computer experience score in the sample was 4.20 (S.D. = 1.76, median = 5). This indicates that participants in average had a medium level of computer experience. There were more female participants, at 59 (60.2%), than male participants, at 39 (39.8%). The general features of the survey participants are summarized in Table 3.

3.2.2. Customer satisfaction of CIBIM design The reliability coefficients (Cronbach's alphas) of the three parts of the questionnaire were acceptable, as they were all higher than 0.6 (serviceability: 0.648, design improvement: 0.903, and availability: 0.653). Table 4 shows the means and standard deviations for the customer satisfaction questionnaire, the results showing that most customers agree that CIBIM has a fairly positive effect.

Considering the serviceability of CIBIM, the participants reported that the simulation simplified their understanding of the apartment unit (M = 4.32, S.D. = 1.25), and that their satisfaction with the communication with the designers through CIBIM was fairly high

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(M = 5.51, S.D. = 0.72). However, the score for convenience of the user interface was less than 4 (M = 3.82, S.D. = 1.41), which is a medium score.

Most of the participants considered that CIBIM improves the design of an apartment unit. In all the factors of design improvement, the mean exceeded 4. Especially for “enclosedness,” “potency,” and “originality,” the mean was greater than 5. Among the eight factors of the SMB scale, the mean of “originality” was the highest, showing that the CIBIM design satisfactorily reflected the individuality of each family. In addition, they reported that the overall quality of the unit design was fairly well improved by CIBIM (M = 5.45, S.D. = 0.79).

The availability of CIBIM was also estimated with high scores.

Customers reported that CIBIM is applicable (M = 5.11, S.D. = 0.80), and feasible for use with similar housing projects (M = 4.70, S.D. = 0.92) and other architectural projects (M = 5.10, S.D. = 0.82). Furthermore, they maintained that CIBIM can improve corporate images in industry (M = 5.23, S.D. = 0.70). Finally, they were very willing to change the unit design in the model house to the new one designed

by CIBIM (M = 5.49, S.D. = 1.03).

Fig. 2. Apartment unit design cases of CIBIM.

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Table 4 Results of the survey on customer satisfaction of CIBIM.

Se1: easiness to understand Se2: user interface Se3: communication with designers De1: pleasantness De2: complexity De3: unity De4: enclosedness De5: potency De6: social status De7: affection De8: originality De9: overall quality Av1: application Av2: housing projects Av3: architectural buildings Av4: corporate images Av5: change to the new one

Mean

S.D.

4.32 3.82 5.51 4.98 4.50 4.92 5.09 5.02 4.54 4.44 5.24 5.45 5.11 4.70 5.10 5.23 5.49

1.25 1.41 0.72 0.76 0.82 0.87 0.96 0.93 0.64 0.70 0.79 0.71 0.80 0.92 0.82 0.70 1.03

Seven-step scale with 1: strongly disagree and 7: strongly agree.

3.2.3. Correlations between survey factors The bivariate correlations between 12 variables – age, cohabiting families, computer experience, three factors of serviceability, design improvement, and five factors of availability – were analyzed in this paper. Regarding the nine design improvement factors, De9, which was a question about the overall design improvement, was analyzed.

To interpret the calculated r value, the following categories were considered: ±0.0–0.2, a very weak to negligible correlation, ± 0.2–0.4, a weak, low correlation, ± 0.4–0.7, a moderate correlation, ±0.7–0.9, a strong, high correlation, and ± 0.9–1.0, a very strong correlation [16,24]. Therefore, only the statistical results reporting a Pearson correlation of ± 0.4–1.0 and p values of b0.01 were analyzed in this paper due to space limitations.

The results for “age” showed that older respondents reported poor computer experience (r = − 0.697, p b 0.01) and found it difficult to understand the CIBIM apartment unit design (r = − 0.546, p b 0.01). They also had difficulty understanding the CIBIM user interface (r = −0.628, p b 0.01). These results suggest that the CIBIM program requires a more customer-friendly interface as well as a manual with detailed instructions.

The results pertaining to “the number of cohabiting families” showed that respondents with fewer family members reported a high level of satisfaction with the new CIBIM design (r = −0.418, p b 0.01), greater expectations for the positive influence on similar housing projects (r = − 0.507, p b 0.01), and greater expectations for enhanced corporate images (r = − 0.405, p b 0.01). They also hoped to change to the new CIBIM apartment unit design (r = − 0.444, p b 0.01). These results show that the model house design did not reflect the needs of small families, which are projected to become the most common type in the future [1].

The result for “computer experience” showed that respondents with more computer experience reported greater ease of understanding the new apartment by CIBIM (r = 0.761, p b 0.01), and greater ease of using the user interface of CIBIM (r = 0.861, p b 0.01). This finding is inconsistent with previous findings [23], which reported that computer graphic models appear to work less well for more experienced computer users.

The results pertaining to “understanding the unit design” showed that respondents who understood the unit design better reported that the user interface of CIBIM was more convenient (r = 0.789, p b 0.01).

The “design improvement” result showed that respondents who agree more that the design is improved through CIBIM reported greater expectations for enhanced corporate images (r = 0.744, p b 0.01) and greater expectations of changes to the new CIBIM apartment unit (r = 0.746, p b 0.01).

Finally, the “corporate image” result showed that respondents who expected more that CIBIM will raise corporate images reported greater expectations for a change to the new CIBIM apartment unit (r = 0.755, p b 0.01). The correlations between survey factors are summarized in Table 5.

3.3. Work efficiency of CIBIM for designers CIBIM minimized the additional commitment and manpower caused by a change in design by decreasing the required modifications of related drawings. This is possible with the parametric principle of CIBIM, from which accurate and consistent drawings of any set of objects or a specified view of the project can be extracted. This greatly reduces the amount of time and the number of errors related to the generating of drawings. When there is a design modification, consistent drawings can be generated immediately at the moment of modification [3]. Table 6 shows the number of drawings that must be modified when there are design changes compared for the conventional method and to CIBIM. It reveals that drawings by a conventional CAD system require 26 times more additional drawings compared to the use of CIBIM. The table represents the number of drawings if only one unit is modified. Therefore, the drawings which should be modified would be proportional to the number of apartment units. For example, if 2603 units which is the number of households of the case project in this paper were applied, to change the entire unit design of the project in the conventional system required 67,678 (2603 × 26) drawing modifications, whereas in the CIBIM system, 2603 drawing modifications are necessary. The effectiveness of CIBIM would be more revealed as the scale of the project became larger. In the CIBIM environment, labor, time, errors, and costs decrease because drawings are modified automatically as they are interlocked and linked to each other based on the parametric system.

Table 5 Correlation matrix of the CIBIM survey.

Ag Cf Ce Se1 Se2 Se3 De9 Av1 Av2 Av3 Av4

Cf

Ce

Se1

Se2

−0.332⁎⁎

−0.697⁎⁎

−0.546⁎⁎

−0.628⁎⁎

0.154

0.023 0.761⁎⁎

0.094 0.861⁎⁎ 0.789⁎⁎

⁎ p b 0.05. ⁎⁎ p b 0.01.

Se3 0.073 −0.027 0.023 0.082 0.083

De9 0.080 −0.418⁎⁎ −0.016 −0.046 0.063 0.092

Av1 0.045 −0.106 0.020 −0.026 0.046 0.096 −0.017

Av2

Av3

Av4

Av5

0.080 −0.507⁎⁎ 0.101 0.136 0.109 0.121 0.270⁎⁎ 0.242⁎

−0.287⁎⁎

0.117 −0.405⁎⁎ 0.044 0.009 0.107 0.026 0.744⁎⁎

0.117 −0.444⁎⁎ 0.086 0.047 0.105 −0.049 0.746⁎⁎

0.008 0.252⁎ 0.263⁎⁎

0.058 0.329⁎⁎ 0.259⁎ 0.755⁎⁎

−0.023 0.378⁎⁎ 0.301⁎⁎ 0.356⁎⁎ −0.019 0.170 0.377⁎⁎ 0.218⁎

S. Lee, M. Ha / Automation in Construction 35 (2013) 424–430 Table 6 Comparison of numbers of drawings to modify.

Drawings

Floor plan Floor plan (Interior) Structural plan Pattern plan Ceiling plan Elevation Partial plan Floor detail Wall detail Ceiling detail Molding detail Wood door and frame Kitchen furniture Room furniture System furniture Bathroom furniture Fire door Shower booth Balcony railings 3D modeling Total

Number

1 1 1 1 1 11 4 3 6 5 1 12 5 8 5 2 2 1 1 1 72

Whether to modify drawings CAD

CIBIM

● ● ● ● ● ● ○ ○ ○ ○ ○ ○ ● ● ● ○ ○ ○ ● ● 26

● ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ ○ 1

●: have to modify drawings ○: do not have to modify drawings.

4. Discussions and recommendations for further studies Firstly, CIBIM is an innovative system for customers. As shown in Fig. 3 which briefly illustrates the work process of the AEC/FM environment, customers in CIBIM can intervene in the early stage of the process. As customers can decide upon the design of their units, there could be various design alternatives which satisfactorily reflect

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the individuality of each customer compared to the conventional 2D drawings environment. Moreover, due to the simulation of unit designs by CIBIM, the need for model houses can be reduced. For this reason, it is not necessary to build disposable model houses and undertake additional unnecessary remodeling of apartment units. Therefore, the construction waste generated as well as the effort and funding associated with the construction of model houses and undertaking a remodeling would all be greatly reduced.

According to the conducted survey, the levels of satisfaction and intention to change to new designs are both very high. It is expected that the CIBIM is applicable to non-housing buildings which are closely related to customers, such as commercial spaces, cultural spaces, and office spaces. Although facilitator's help was provided, it still requires effort to become familiar with the CIBIM program. Therefore, the creation of a more customer-friendly interface and a manual with detailed instructions are necessary. More detailed and specified information about the difficulties in using CIBIM must be investigated for its effective use.

Secondly, not only for customers but also for designers, CIBIM is a satisfactory system. Due to the parametric modeling methodology, CIBIM attenuates the effort, time, and number of errors when designers modify a unit design. At the early stage of CIBIM design, much effort and time may be required as compared to the traditional method. However, these weak points can be offset as the project develops and design changes.

Thirdly, if this research is developed further and information about finishing materials of apartment units is added, parametric quantity takeoff and a cost estimate for each unit would be possible.

This early interim estimate helps consumers to manage their budgets and confirm the design and price of their particular unit (see Fig. 3).

Moreover, contractors can facilitate quantity takeoff and cost estimate at an early stage of the work process more easily using CIBIM

Fig. 3. Comparison of the work process of the conventional (upper) and CIBIM (lower) AEC/FM environments.

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data. This would quicken and simplify the construction of various types of units in apartment housing. CIBIM can become an efficient tool to accumulate, assemble, and estimate the complicated information pertaining to finishing materials of numerous units.

Finally, as the design and construction of apartment is a team activity, CIBIM should be used in collaboration with work partners.

The problems which arise from the sharing of spatial information should be considered [8,22]. Therefore, further study considering interoperability, i.e., the ability to interchange data which is structured and computable by another application when exported and imported (Industry Foundation Classes (IFC) is one of the main model for building design and construction [2,3,20]) of CIBIM is strongly required (see Fig. 3). To apply the CIBIM concept to the construction of an actual apartment project, the data between CIBIM and supporting tools (circulation and security assessment, structural and energy analysis, and quantity takeoff and cost estimate applications [2,3]) could be interchanged smoothly among designers, engineers, contractors, and other stakeholders.

5. Conclusion In the competitive apartment housing market in an urban society, customer-oriented designs which satisfactorily reflect the individuality of each family are critical. To realize this, designers have to provide customers with individually tailored unit designs. In order to meet various customer needs efficiently, innovative and radical changes in the traditional design process are necessary. The parametric CIBIM design can meet these various needs of customers and reduce the labor and time required by designers, engineers, and contractors.

CIBIM is a win–win strategy for customers, designers, engineers, contractors and other stakeholders.

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