Embedding Data

Each parametric object can be tagged with a unique set of data that can be recalled at any time. This technique is also known as embedding data. Processing the gath-ered data, teams develop protocols and methodologies of data organization for ease of retrieval. One common example is door and window schedules as shown in Fig-ure 5.6. Like a good search engine, without tagging the data for retrieval, the data is useless. Teams must identify which information should be gathered and incorporate it into the database, anticipating who will be using it at later stages of the project.

An example is to trace the selection of a common building element such as fenestration. As the architects develop their design, they select a window based on multiple criteria. Aesthetic consideration is just one facet of the window. Other criteria are its energy rating to meet codes, its materials for sustainability and main-tenance, the operation for natural ventilation, the security concerns of the project, the projected life, and glazing for day lighting. Some of these address program-matic concerns, other functions or user friendliness, and how they will enhance the quality of the spaces that they help to define. Program goals are part of the data-base developed in the planning phase. These goals assist the architect, for example, when selecting the type and amount of glazing to be used. As the project progresses through design, how well the windows support the building design is evaluated.

The natural ventilation of perable windows is a consideration in the design of a building’s mechanical systems. Similarly the natural light provided by windows is a factor in a project’s lighting design. An architect may specify a particular window manufacturer’s system. During bidding the contractor may suggest alternatives. It is then important that the goals from programming through design are easily re-trievable from the database to check the alternatives for compliance. As the period of occupancy is now a more integral influence on the design choices, the long-term maintenance and durability of the window units are also parts of the decision pro-cess for the choice of the window unit.

Architects are able to include much of the specification data for a window or any other building component in the parametric objects that they use. In Figure 5.6 you can see the standard window information parameters available along with custom user-defined parameters for project-specific parameters. Many of these pa-rameters are shown in project window schedules. Any data can be extracted in schedules that assist designers, contractors, and facility managers in streamlining their workflow. For example, they can list all windows by manufacturer to assist in pricing and ordering. Cost estimators’ schedules would be concerned with unit costs, and again they might also be sorted by manufacturer. During construction, schedules can be generated from the project database to assist directing where each unit will be installed, by floor and room. Interior designers can also use the window information to obtain finish information as they develop color and finish palettes.

Facility managers will rely on the specifications to be included in the database for

5.10 Embedding Data 57

scheduling of maintenance, repairs, and replacement. Specifications and product literature are included by linking to PDF versions of this data. Facility management teams can bring up this information as part of their workflow processes. The man-ufacturer’s Web sites can also be included for direct links to current information.

This ability to have all relevant information about a window or any other building component or system, along with the decision-making process that led to

Figure 5.6 Window parameters. This image shows the many parameters of the single window object.

Each parameter can be changed without affecting any other. When multiple windows are selected, a single parameter, such as a frame color, can be changed without affecting any other parameter even when each window is different.

58 The BIM Process the choice, is of great value for all team members throughout the life of the build-ing. The information contained in the project database is not only accessible to all teams, but can also be arranged in multiple groupings to aid each team with its scope of work.

5.11 3-D Visualization

The virtual models are an integral part of the workflow. Designers beginning in planning are working in 3-D representations of the spaces and buildings that they are creating. There is direct and instant feedback from what is being created, in con-trast to working solely in 2-D views where much information is left to the viewer to complete. As design progresses, any team member can view the work in its vir-tual model mode supplementing the documentation, which remains largely as 2-D views. The human brain can more easily grasp a virtual model representation than the same data in schedule and list format. This friendly-user interface facilitates design comprehension. Physical models are still often made, but many are now done in a virtual form. This by-product of constructing a virtual model assists the project from design through occupancy. Designers create their buildings and do so completely modeling the building, not just parts of it as minimally necessary to explain their ideas. They are also forced to design, and therefore take into account, all of the building when they model it.

The complete virtual model takes the guesswork out of the jobs of contractors, and estimators because the model provides complete building information. Fabri-cators are able to create their own virtual models for mockups, realizing consider-able savings to both the project schedule and cost. Details that were worked out in the field or in physical models can now be completed virtually.

Contractors spend less time resolving clashes in the design as these are resolved during the design phase. As changes are made during construction, they update the BIM database and the virtual model. Using the virtual model, they attach dates to the various components and assemblies. From this data construction is able to create a simulation of the building. This assists contractors with scheduling and also simulating alternatives in unforeseen circumstances such as delays in material delivery. At the end of construction the owner has both an actual building and an exact duplicate of it in a virtual representation.

Virtual models are also used in related work such as installation and mainte-nance models. Using a virtual model rather than filming an installation allows the installer to view the work from any angle and to zoom in and out as necessary to better comprehend the process that he or she will be using.

Facility managers and their teams are able to use the virtual models to assist them in planning, maintenance, controlling costs and scheduling work. They have accurate models of the complete building. They now have to maintain the BIM model if they are to continue to benefit from using virtual models. Depending on the size of the organization and the database, its virtual model may be maintained in-house by staff architects and engineers or they can outsource this work to a spe-cialist. Owners and facility managers are now training their staff in BIM applica-tions, supplanting the 2-D CAD work that has been the standard.