Entrant details
Role or Job Title on the Project
BIM workflow integration between Architectural and Structural designs for the prefabrication in LWF
Employer
University of São Paulo - USP
Employer Role
Academic or Research Institution
Are you or your employer a member of buildingSMART?
No
Submission details
Submitting Party Company Name
University of Sao Paulo - USP
Submitting Party Company Location
Sao Paulo, Brazil
Submitting Party Role on Project
Tecverde Wood Construction Co.
Submitting Party Company Website
Full Project Name
BIM integration in the design flow between Architecture and Structure for prefabrication in the LWF
Project Location (Country)
Brazil
Project Objectives
As a general objective, this research intends to analyze the possible BIM contributions and limitations to the practice of prefabrication.
As a specific objective, it intends to investigate how the use of integrated BIM to the prefabricated industrial process by the LWF can contribute to add value in the production chain in the AEC, as well as to discover what the limitations are. We will present a technical solution for BIM integration in the design flow between the Architecture and Structure disciplines based on the case of Tecverde Co., using the following standards and open methods: IFC, IDM, and MVD.
openBIM Achievements
The research has studied a Brazilian housing prefabricator who uses the Light Wood Frame system. Although the company has experimented a huge growth since its foundation, it has BIM workflow issues, involving the structural analysis phase. Once the conceptual design is conceived, it is sent to the structural design company in paper-based documentation. This force the structural engineers to redesign the architectural walls from scratch. After identifying the issues using the IDM standard, the research proposed an IFC4-based data exchange, building a specific MVD for that purpose. The OpenBIM could solve a core time-consuming to the overall process though.
openBIM used
IFC4, MVD
Software used
Revit, SEMA, Dlubal RFEM and IfcDoc
Strategic Alignment
The OpenBIM was the core of the research, which has investigated how the buildingSMART initiatives can help the AEC. We´ve perceived that the exchange BIM data between authoring tools work well, but it suppresses the stakeholder´s right to choose from what tools he or she prefer to work with. In this scenario, OpenBIM bring productivity for the SMEs companies, which composes the majority of the AEC businesses.
Highlights
- Handover shortage within stakeholders
- Mitigation of human error, which was common
- Avoidance of buying native exporting BIM modules to SMEs
- Improvement and softness in the overall workflow
Project Address
R. Pascoal Fernandes Leite - Thomaz Coelho, Araucária - PR, Brazil
ZIP Code: 81020-490
Project Type
Residential
Size of Project
Total square meters = 2,600 m2
Detailed description of the project
Historically, the Architecture, Engineering, and Construction (AEC) sector deals with problems related to its productivity. Both problems are the different faces of the same coin: low productivity causes an increase in costs which, in turn, feeds back the low productivity through the disincentive to invest in viable solutions. This seeming paradigm has been solved in other industries but has never been so far in the AEC. Several approaches in the AEC, at various times, have been tested by the industry and have achieved somehow their successes.
On the other hand, studies in the world market show that there is a renewed interest in the use of prefabricated products and the development of modular projects arising from the broad and growing adoption of BIM. The history of the application of prefabrication and modularization in production at the AEC is not new, so to defeat low productivity. The use of an Information and Communication Technology (ICT) such as BIM creates a synergy with industrialized construction processes, which points to the importance of ICT.
This work addresses BIM integration through the Industry Foundation Classes (IFC) scheme, managed by buildingSMART to contribute synergistically to the prefabrication, based on the analysis, mapping and proposition of a design flow for a construction company dedicated to the prefabrication and assembly of wooden buildings addressing the Light Wood Frame (LWF) construction system.
Thus, this research analyzes and proposes a BIM interoperability solution between the Architectural and the Structural Designs through the IFC scheme. The proposed solution uses the integrated IDM / MVD methods (Information Delivery Manual / Model View Definition) as tools for discovering which dataset should be part of the Exchange Requirements (ERs) for interoperability to occur, based on the requirements of the receiving agent, i.e., Structural Design.
Once the exchange requirements are identified, Exchange Models (EMs) will be proposed, which will serve as a guide for possible future automation of the project process through the implementation of the corresponding MVD. Thus, it is intended, from the case study of the company, to generalize the exchange requirements necessary for BIM interoperability in the process of designing residential units by the LWF system.
As a general objective, this research intends to analyze the possible BIM contributions and limitations to the practice of prefabrication in AEC.
As a specific objective, it intends to investigate how the use of BIM integrated to the pre-fabricated industrial process by the LWF system can contribute to add value in the production chain in the AEC, as well as to discover what the limitations are. We will present a technical solution for BIM integration in the design flow between the Architecture and Structure disciplines based on the case of Tecverde Engineering Co., using the following standards and open methods: IFC, IDM, and MVD.
The Design Science Research was selected once it is keen to deal with artificial and human creations. As a method which concerns with the system designs, its goal remains in the pragmatic vision of the solution-oriented target. Our choice was made up to support the prescription principle that the method is based on, which fits our research goals.
Through a preliminary visit to the company, it was proposed to intervene in the company's design process to adjust one of its production bottlenecks (the execution of the executive design) through the adoption of BIM interoperability between the Architectural and the Structural Design (nonexistent nowadays). The company uses Revit, RFEM, and SEMA software to develop their projects. Preliminarily, the company's project flow will be mapped using the BPMN language, and the subsequent implementation of the integrated IDM / MVD method in the company context. The research artifact is, therefore, the proposed MVD for BIM interoperability between specific architecture and structural design.
One can understand interoperability as the possibility of exchanging information between distinct software, in a transparent way, through a digital model. During the project development flow of a venture, the team can utilize a variety of expert applications in each discipline. Interoperability is used to maintain the collaboration of the interdisciplinary team without incurring the re-entry of data and using the same database.
The Tecverde Co. is a construction company commonly classified in the market as a "construtech." It is a joint-stock company focused on the manufacture, supply, and assembly of industrialized buildings by the LWF system. The company pays its scientific support bias in its corporate vision and its business values. The construction system is industrialized, which increases quality and accuracy. Today, the company has financial support from foreign investment funds and the promotion of national financial institutions. The appeal of sustainability and the capacity for innovation were determining factors for such funds to invest in the enterprise. Its competitive radius of operation in Brazil is around 1,000 km from its factory. The average productivity achieved by the company is 50 houses per month, employing 18 factory workers.
The construction elements were associated with the IFC4 Addendum 2 objects obeying the function of each element. The schema allows to represent a wall panel both by the IfcWallStandardCase object and by the IfcWallElementedCase object (both types related to the IfcWallType object), as well as its structural members can be represented as both IfcColumnType and Beams (IfcBeamType) (vertical and horizontal structural parts), or just by the IfcMemberType object.
We´ve detailed the found IDM and adapted it to the interoperability needs. Then, we´ve gone through the MVD existing Concepts to relate them to the specific workflow requirements, creating a specific MVD.
The conclusions are the following. Although interoperability is well resolved in authoring tools, it suppresses the right to choose and have a high cost! Prefabrication has synergy with BIM, but integration mechanisms are still lacking. IDM was sufficient for the discovery process, but its refinement takes time. The proposed MVD can be generalized and a new technological cycle is enabling a new “leap” in prefabrication, using open standards.
Detailed description of openBIM on the project
In brief, we have explained the IFC schema structure, the IDM and the MVD as well in order to give the reader a general idea of how these buildingSMART standards are related. Then it was presented the IFC objects and its redundancy, explaining that a given physical object can be represented in various ways in IFC. We´ve also analyzed some IFC files exported from Revit and SEMA export modules, pointing out that these modules can produce mistakes and information, posing a difficulty to overcome in OpenBIM. As our aim was to develop a specific exchange MVD, we have related the possible existing IFC4 objects to every single piece used in the LWF prefabrication in the Case Study, creating a detailed Exchange Requirement list of its related objects, concept and the needed attributes to be present in the exchange model. Then we´ve used the IfcDoc to deploy the documentation.
In detail, the IfcWallElementedCase was created in IFC4 to represent cases of all walls that can be decomposed into layers so that these layers can be composed of subassemblies aggregated by the entity IfcRelAggregates. This is the case of LWF wall panels, which are composed of the core layer and the coverings, being this, therefore, the appropriate form for representation of panels in LWF.
The subparts of the wall assembly are the core and the coverings, related by the IfcRelAggregate entity. Each of the layers may have subassemblies which can be made up of a few layers each. The IfcBuildingElementPartType object is intended to represent larger, subordinate elements of the wall that have layers with different geometric representations. The inner stud layer is attached by the IfcElementAssembly object, IFC entity intended for the complex assembly of parts, made by several other parts, with different possible geometries. This is the case of the core, which is composed of several structural members (IfcMember) with various geometries, orientations, and locations within the assembly.
following IFC representations of the elements are numbered:
- Vertical and horizontal uprights: IfcMemberStandardCase
- OSBs inner and outer coverings: IfcBuildingElementPartType (typeEnum = Precast Panel)
- Waterproof Blanket: IfcCoveringType (typeEnum = Membrane)
- Cementboard sheet: IfcBuildingElementPartType (typeEnum = PrecastPanel)
- Basecoat joints treatment: IfcCoveringType (typeEnum = Wrapping)
- Acrylic texture, with no representation need herein
- Plasterboard: IfcBuildingElementPartType (typeEnum = Precast Panel)
- Acrylic painting, also with no representation need herein
The schema allows to represent a wall panel both by the IfcWallStandardCase object and by the IfcWallElemented Case object (both types related to the IfcWallType object), as well as its structural
members can be represented as both IfcColumnType and Beams (IfcBeamType) (vertical and horizontal structural parts), or just by the IfcMemberType object.
Metal fasteners such as nails, nail plates, screws, and angle brackets were related to the standard objects considering their fastening method within the IFC scheme. The bolts are generally associated with the IfcMechanicalFastenerType type-elements, and the metal brackets and connectors, associated with the IfcDiscreteAccessoryType type objects.
The covering plates were generally associated with the IfcBuildingElementPartType objects. Finally, there is the IfcCoveringType which was used to represent the waterproof and acoustic insulation layers, such as the Tyvek® membrane and the layers of glass and rock wool.
The objects in the IFC scheme acquire a geometric and/or spatial representation from the specialization of IfcProduct on, and its subtypes. Therefore, it is in this supertype level that they acquire the ObjectPlacement and Representation attributes, related to the location and physical representation of the object in space. When thinking of a cube, for example, one can consider several possible representations of the same element. It could be either its three-dimensional representation in space, its projection on Cartesian planes, its two- dimensional representation in a cross-section or even the different ways of composing this cube as an extruded solid (Swept Solid ), a set of planes (boundary representation or B-rep) or a set of lines and cardinal points (wireframe). All these representations can be associated to the object at the same time, allowing each of them to be available for a particular purpose in the project.
The difference between the IfcProduct and its type, the IfcTypeProduct is that the first allows the existence of individual physical objects, while the second also allows the existence of copies of itself, with variations of scale, rotation, and position. The IfcTypeProduct has a typical structure mapped to its Representation Map attribute, which is based on the IfcRepresentationMap object. The latter object is part of the IFC Resource Layer and allows the transformation and copying of a given object according to pre-established rules, just as suggested by the ISO 10303-43: 1992 concepts. One can rotate it from the mapped representation, change its proportions, and copy it, creating different instances of the object even though this element has a unique geometric, logical pointing.
Another issue observed regarding the relationship between IFC objects is that it cannot be viewed in the IFC scheme. These objects or “objectified relationships” are semantic entities that dictate how does one or more IFC elements is positioned in space, and how do they relate to one another, but they cannot be represented visually.
After doing so, we´ve defined which were the design elements to be present in the structural design discipline by the IDM method, and then, related them to the existing buildingSMART model concepts to build up the MVD documentation. Initially, the MVD called “Architecture To Structure” was created in IfcDoc 10.8, where the ER named “Arch to Structure Exchange” was built, whose assigned code was “er_ArchToStruct” as recommended by ISO 29481-1. The next step was to relate, in the newly created MVD, each applicable entity (each root concept - mvd:ConceptRoot) to the relevant model concepts (mvd: ConceptTemplate), according to what was previously identified in the IDM. The model concepts were selected from the list available in the IfcDoc itself, coming from pre-registered views (MVDs). Only then were the parameters of each model concept configured, such as the level of requirement as Mandatory or Optional. The last step was the publication and generation of the HTML files.
Benefits from using openBIM
There is no unique BIM software capable of hoarding all disciplines. Some of them can operate various tasks and deal with many disciplines at once, but no one can be the best in all tasks at once. Considering this, openBIM makes it powerful the potential deployed by BIM, once it allows all stakeholders choose what software (or set of software) to work with, according to its special needs. It becomes even more useful when used not only to the design and construction phases, but to link to the operational tasks during the building´s life (Facility Management). Owners who build an AEC asset to further exploit it, like hotel groups, commercial buildings, and industrial built-to-suit plants, can harvest even more benefits from BIM then regular design and construction companies. Our research has approached the interaction between BIM and Prefabrication, and in this context, we have listed some advantages as follows:
BIM has great potential in ameliorate the AEC´s productivity, but it has sort of “right conditions” to achieve so, listed below:
- Hierarchical structure of prefabricated products – once BIM is not necessarily made for the prefab specifications, it has to be adapted to these conditions, like, for instance, there must be developed not only a specific library in an appropriate manner – Level of Development (LoD), and semantic embedded data. Other point is that it needs an appropriate environment, which can be achieved by developing an appropriate template to work with.
- Assembly sequence must be present - the Design for Manufacturing and Assembly (DfMA) concepts must be present since the exceedingly early stages of the design phase. Not only the design “per se” can have particularities, but also its assembly sequence must be considered. For this to happen, the industrial designers must be among the collaboration stakeholders’ team, since the AEC design professionals (architects, engineers, etc.) are not used to work in fabrication projects, like solving connections and joins.
The OpenBIM thus, improve the collaboration, shortening the time-to-market of an AEC asset. Sets of specific MVDs can provide a continuous information flow between diverse authoring software. In our specific research´s panorama, we found also that there is always an optimum level of prefabrication for each case, depending on the distance between the fabrication and the site, the site conditions to accommodate chunks, parts and equipment (like cranes and trucks), among others.
"We were able to identify where we need openBIM to develop further."
It is suggested as a continuation of the development of our scientific exploration, some lines of research that can contribute to add value in the production chain at AEC, more specifically with regard to the design phase, through the adoption of OpenBIM and the prefabrication:
a) in the line of research that verifies the synergy between BIM and prefabrication, a possible research could investigate what are the characteristics that BIM should have to deal better with prefabrication. In the opposite direction, it is also possible to evaluate which are the off-site construction (OSC) and prefabrication processes that could be better suited to the BIM process, thus forming a two-way street to better enable the extraction of the full potential of this synergy;
b) a second line derived from this research could be the study of the impact of the emerging need for the adoption of DfMA concepts for the BIM project flow in AEC, so that the research could generate collaborative design guidelines for the integration of different design disciplines and the different information needs for the production, transport and assembly of prefabricated buildings.
BIM Uses were defined on the project
I agree to be contacted about the project BIM uses outside of this awards program.
Stakeholders
Tecverde Construção Inteligente S/A, Araucária, Brazil, Director - LWF fabricator and construction company, Pedro Virmond Moreira
Stamade Projeto e Consultoria em Madeira Ltda., Structural Engineering Design Co.,
http://stamade.com.br/, Owner - Wood Structural design specialist, Guilherme Correa Stamato
