In the contemporary world of the Architecture, Engineering, and Construction (AEC) industry, BIM has become not only an advanced solution but an obligatory tool. It provides teams with a reliable basis for decision-making as well as an effective means of coordinating the design, construction, and operation of buildings throughout their whole life cycles.
The structured outputs produced in the course of BIM implementation – BIM deliverables, which include 3D models, 2D contract documentation, and rich spreadsheets – play a pivotal role in facilitating the decision-making process and smooth project handovers. These BIM deliverables evolve in the course of the project in accordance with the Level of Development (LOD) scale.
The guide will walk you through five major project stages and the BIM deliverables that have to be provided at these stages, and describe the importance of having a proper BIM Execution Plan (BEP).
Understanding BIM Project Stages and LOD Concept
The BIM project usually follows a certain framework, like RIBA or AIA phases, which involve the following stages: from concept to operation. One of the key concepts of a BIM project is LOD, which reflects the degree of detail and reliability of the model created.
LOD 100 (Conceptual): Basic massing and volume.
LOD 200 (Schematic Design): Generalized systems and assemblies.
LOD 300 (Design Development): Accurate geometry with detailed information.
LOD 350 (Construction Documentation): Detailed coordination between systems.
LOD 400 (Fabrication): Precise fabrication-level details.
LOD 500 (As-Built): Verified field-representative model.
BIM Execution Plan represents a project roadmap and specifies LOD milestones, data standards, and handover procedures that prevent information gaps among stakeholders. The classification system used to define the contents of BIM deliverables at each stage (for example, Uniclass classification) is also defined by the BEP.
Stage 1: Concept and Feasibility at LOD 100
The first stage involves testing the project's viability on the particular site and within a particular budget. In LOD 100 BIM modeling services, the focus is on visualization of the project rather than detailed modeling, which could slow down this phase.
Preliminary 3D Massing Models (.rvt, .ifc, and other formats): These models provide stakeholders with an overview of the building (its form, footprint, and height).
Site Analysis Reports: These reports describe aspects of site conditions such as topography, zoning, and setbacks, and other important information that should be considered during feasibility studies.
High-Level Cost Estimates: These estimates, which are based on the gross volumes of the massing model, give stakeholders an idea of the financial scope of the project. Some of the information to be provided at this stage may also include performance criteria of the building.
These BIM deliverables are crucial for gaining client buy-in and setting project goals without getting involved in premature detailing, which can result in costly redesign in the future.
Stage 2: Design Development and Coordination at LOD 200-300
During the second stage of BIM, project models develop further and integrate architectural, structural, and MEP systems design. The real power of collaboration and BIM implementation becomes evident at this stage.
Federated Models: All models of different disciplines are federated in one view. Federated models are often hosted in cloud environments for collaboration.
Clash Detection and Simulations: Clash detection is performed using the federated model, and some of the simulations (daylighting, airflow, and energy performance simulation) are conducted.
2D Contract Documentation: 2D drawings (plans and sections) are provided directly from the federated model. Thus, there is a correspondence between visual documentation and the model, which is a common requirement to be followed in accordance with BIM protocols.
Data-Rich Models: Models at LOD 200-300 include non-graphical information like classification of objects (Uniclass) and asset information to be used for COBie handover.
Thus, investing in professional BIM modeling services at this stage will prevent RFIs and change orders during the construction stage.
Stage 3: Construction Documentation and Fabrication at LOD 350-400
During the third stage, models evolve to a construction-ready level (LOD 350) and a fabrication-specific level (LOD 400). The focus here is on precise information for construction.
Detailed Fabrication Models: These models include all necessary information about tolerances, connections, and annotations for elements like steel structures, MEP systems, and prefabrication.
BIM Sequencing Visuals: Such animations illustrate the construction sequence, which includes crane paths, phased installation, and other information related to logistics.
RFI Logs and Change Order Trackers: RFI logs and change order trackers are often connected with particular elements of the model.
Access to Models On-site: Using mobile applications, field teams can access the model on site, make markups, and make sure that materials and equipment are delivered to the site in the most efficient way.
Thus, these detailed BIM deliverables help to avoid any rework which can occur because of issues discovered much later after concrete pours or steel installations.
Furthermore, using digital means helps to draft the required Employer's Information Requirements in accordance with the BIM Execution Plan (BEP).
Stage 4: Handover and As-Built Models at LOD 500
The final stage of construction is the creation of LOD 500 models which reflect the as-built condition verified by laser scanning, drone photography, and total stations.
Verified As-Built Models: Models are updated in accordance with the as-built condition, including asset tags for doors, HVAC units, light fixtures, and other equipment.
COBie Spreadsheets: Construction Operations Building Information Exchange (COBie) format provides a list of equipment, spaces, and maintenance needs for facility management purposes.
O&M Manuals: Operation and Maintenance manuals with warranties are attached in the model. This information includes such properties of assets as lifespan and warranty start date.
These BIM deliverables constitute a digital twin for facility management and further renovations of the building during its lifecycle. The information is provided not only in files but in a Common Data Environment (CDE) in order to conduct predictive maintenance and renovations of the facility.
Tips for Smooth Implementation of BIM
In order to implement the process described above, there are several practices which can significantly facilitate it. First of all, developing a BEP at the very beginning of the project is obligatory. It should define LOD milestones, responsibility matrices, and data standards in order to avoid any misunderstanding. Moreover, using cloud-based solutions like Autodesk Construction Cloud will help with version control and collaboration. Holding model coordination meetings and performing automatic quality checks of geometry and data completeness is important. Finally, training all teams regarding LOD and data requirements from the very beginning of the process will help to maintain consistency of the process. Treating BIM as a profit driver at every stage of the project will help to reduce the cost by up to 15-20%.
Commonly Asked Questions
Q1: What are the main BIM deliverables at LOD 100?
The main BIM deliverables at LOD 100 include preliminary 3D massing models in .rvt and .ifc and other formats, site analysis reports, and high-level cost estimates based on the gross volumes of the massing model. These BIM deliverables help to gain stakeholder approval and set project goals without unnecessary detailing.
Q2: How are LOD 200- 300 models used for design coordination?
LOD 200-300 models include integration of architectural, structural, and MEP systems in the federated model, clash detection, and simulations. It allows conducting real-time feedback using a cloud environment and producing 2D contract documentation directly from the model.
Q3: What BIM deliverables are provided for construction documentation?
The BIM deliverables that have to be provided for construction documentation are LOD 350-400 models with fabrication-level details, 4D BIM sequencing visualizations, RFI logs, and logistics planning.
Q4: What is included in LOD 500 as-built BIM deliverables?
LOD 500 BIM deliverables include verified as-built models, COBie spreadsheets with equipment and maintenance information, and O&M manuals with warranties directly in the model.
Q5: Why is BEP crucial for deliverables definition?
BEP defines LOD milestones, data standards, and handover procedures, which will help all stakeholders coordinate their actions and avoid misunderstandings.
Q6: How do BIM modeling services help the project?
BIM modeling services allow for LOD-compliant models, federated outputs, and as-built deliverables in order to reduce RFIs, change orders, and rework. In addition, it provides predictive maintenance and lifecycle value through digital twins.
For those companies that want to get assistance with LOD-compliant deliverables and smooth handovers, the best choice would be a partnership with experienced providers. CAD Drafting Services will provide you with the full range of guidance and execution in the BIM sphere. Contact us to learn more about our services.