The acronym BIM stands for “building information model” and includes not only the geometry of the building, but all the means and methods data necessary to construct the building. The key is to integrate the known geometry (from popular modeling applications like ArchiCAD, Revit, Tekla, SketchUp or even IFC files) with construction-caliber quantities, scheduling tasks and productivity rates, material and labor costs, not to mention warranty and installation information, for the project. And all project stakeholders can see what happens when a change is made to the design of the building – how it impacts the schedule and how it impacts the budget. This means data-driven decisions instead of budget-busting mistakes.
Many AEC professionals understand the highly-visual nature of 3D models to express design intent, but might not be familiar with BIM for Construction. It all starts with five key concepts which inform the five BIM dimensions.
Number One. Change Management: One of the first hurdles of any construction project is to track changes between 2D drawing sets and 3D models. It would be remarkable to compare the details in the 2D drawing with the 3D model. This hydrid 2D-3D view is essential as firms receive both drawings and models – and this ensures a coordinated design from the start. This means no second-guessing the design; this means exact quantification; this means no missed scope in the estimate.
Number Two. Construction-Caliber Quantities: Instead of using design team’s simple geometric measurements and counts, quantification methods must be based on builders’ needs. This means dozens of complex properties and quantity fidelity for each building element. These highly sophisticated quantities then power more detailed estimates and schedules.
Number Three. Location-Breakdown Structure: Organizing the construction project by locations is intrinsic to highly-detailed income and expense curve reporting. Quantities by location, costs per location, crews per location, etc. all inform this reporting to better manage cash flow. Look for a solution to provide both geometry splitting and location-based quantities. And it should be non-destructive – the solutions should keep the original elements so you don’t need to keep returning to the original BIM model to make tedious changes. All the locations are persistent and can be applied to new versions of the model.
Number Four. Evolutionary Cost Planning: With the advent of BIM, design teams are able to release many more updates to the project; and hence, the estimating team needs to understand quickly what has changed in the design and how those changes impact the cost and schedule. A brilliant solution would be highly-visual to better communicate these variances to the Owner and help the Owner determine which design decisions make the most impact.
Number Five. Build-to-Design; Design-to-Build: Even the best-laid plans can fail due to a lack of clear communication. However, that is not the case with integrated field layout solutions. Points should be plotted once in the solution and shared with the hand-held laser tracking devices in the field. The actual points are then approved for tolerance, for code, or even for payment.
Caption: BIM for Construction must boil down to this: no second-guessing the design, exact quantification by location, no missed scope in the estimate, sticking to the schedule with solid production control, and modeling useful information for the field team.
These five basic tenets of BIM for Construction manifest themselves in the key dimensions of BIM:
2D BIM: How many times have you missed a detail in the drawings that changed from one set to another? What details are in the drawings, but not in the model? A powerful 2D solution will include a change detection tool for 2D drawing sets (and even 3D models!). This version review step is critical for design coordination from the start of the project. Additionally, good construction coordination should yield both composite drawings and 2D installation drawings. These are great deliverables for field use because the last thing you want are subs going up and down ladders or coming back to the trailer to get a question answered.
3D BIM: It is one thing to identify clashes between models and quite another to resolve the problems in preconstruction, thus shortening the schedule and saving the budget from costly re-work. Streamlining the RFI process is integral to any project. The solution should include clouding changes in the 2D drawings and clashes in the 3D models and then managing the communication flow about these issues, identifying their impact on schedule and budget, and resolving them.
4D BIM: Scheduling is comprised of four components: quantities by location, flowline theory, on-site production control, and 4D movie simulations. Consider scheduling solutions powered by location-based management system which relies on the progress of work crews as they migrate (or flow) through a building. The goal is to preserve the work crew's productivity rate as they move from location to location and minimize the number of starts and stops.
5D BIM: The 5D BIM estimating applications should include construction-caliber quantities, iterative cost planning, budget tracking, and target cost comparisons for design changes. Your construction estimating software should bridge the gap between 2D drawings and 5D BIM models by recognizing model-based and non-model-based elements in the estimate and visually linking the cost items to the model elements.
6D BIM: 6D BIM models are another natural deliverable from good construction coordination. This model contains the room elements, such as room name, number, and space type connected with asset information such as manufacturer, model numbers, serial numbers, and any operations and maintenance requirements. So instead of the encyclopedia set of three-ring binders at the end of the project, GCs can give the Owner a 6D BIM model complete with all the information their facilities' team needs.
The solution you choose should transform 3D BIMs into information powerhouses integrating construction-caliber quantities by location, 4D scheduling data, and 5D cost estimating data. The result is a live construction management model that empowers users to create constructability analysis, estimates, and Flowline™ schedules and to accurately and rapidly assess the impact of changes to these plans, whether those changes occur during preconstruction planning or during the project’s build phase.
This integrated approach to construction management is a very powerful strategy. The entire company benefits with fully-integrated planning and controlling solutions for design, cost, and time. Firms leading the Virtual Construction charge have proved this to themselves by literally picking the jobs they wanted to win, developing the best plans, recruiting the best teams, executing more effectively in the field, and delivering a new and exciting owner experience. It is clear that improving the way we bid, manage, execute, and learn from our construction projects pays dividends.
Download the BIM Checklist learn about the functionality that powers BIM for Construction. You can then use the checklist for three distinct purposes: (1) compare BIM vendors’ capabilities, (2) see which capabilities you would like to offer your Owners, and (3) compare your firm with the competition.