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  Taking Budgeting to a New Level with BIM

BIM (building information modeling) is moving from buzzword to business tool. While not all construction firms routinely use BIM software, many of the early adopters are finding new uses and technologies to solve problems and add value.

In this article, we’ll look at two cases using “macro” BIM software tools to make development go/no go decisions and keep a target value design on track. Macro BIM is a building information model, made of higher level building elements. It’s used for macro level analysis including visualization, spatial validation, cost modeling/estimating, phasing/sequencing, energy performance, and risk analysis. Macro models are meant to be built quickly, to rapidly analyze multiple concepts before using a more detailed “micro” BIM tool. Macro BIM authoring tools use parametric variables and inferencing capabilities to quickly build enough relevant data for analysis.

Data Rich Site Master Planning
Post real estate market crash, savvy owners and construction firms have leveraged macro BIM technology to improve their ability to evaluate how a particular site matches the intended use before the land is purchased. Accurate estimates from general contractors can help an owner to determine whether a project is viable, at the earliest stage. Using macro BIM applications, owners and developers can quickly evaluate the feasibility and costs of building the project on a particular site. There’s also the benefit of seeing it and better understanding the assumptions the estimate is based on.

The director of pre-construction for a major real estate development company, known for a signature product, says that in his business, the site is critical. “Typically the designers can play around with the buildings, elevations and finishes on a project to meet the budget, but the site – we can’t control that. It has to be engineered. The sooner we know what the issues are, the better.”

Garry Myers is a Senior Construction Estimator for Clark Construction Company, an ENR Top 400 contractor, headquartered in Lansing, Michigan. He has 30 years of estimating experience, and spent much of the last ten creating conceptual master planning estimates for major development projects. Myers describes how he uses DProfiler, a macro BIM application from Beck Technology, for preliminary cost estimating of site master plans. “I use DProfiler to determine a project’s costs while there’s little information, to help the owner make fundamental decisions,” says Myers. “I create high level conceptual models and then experiment with different configurations for the buildings within the site to see what the cost ramifications will be.”

In early 2010, Myers began work on a proposed $100 million site development project, creating a conceptual master plan with detailed costs that the developer would use to determine whether to move forward with the project.

The proposed site was attractive from a market perspective, but posed serious engineering challenges. The 50 acre infill parcel had dramatic 30-foot elevation changes from the north end of the site to the south. With only the developer’s napkin sketch, Myers had to house more than a dozen buildings – retail, office, residential, parking structures – on the site. He also had to marry the site’s proposed network of roads and pathways to the existing transportation network surrounding the site.

Myers first imported the proposed site’s topography from Google Earth™ into his macro BIM application, set elevations for buildings and parking structures and modeled all the structures for the virtual site plan. He used the software to estimate the cost of the buildings and the site, computing the grade, cut and fill costs and produced a color-coded image illustrating the cut and fill areas visually. Nearly 600,000 cubic yards of dirt had to be redistributed to balance the site.

Next, Myers explored site planning alternatives, creating virtual scenarios based on building and site item location and orientation, as well as changes to the building pad and site item elevations. He advised the owner’s representative on the site’s issues and related costs for each scenario.

The outcome? The significant challenges associated with this site have the developer leaning toward a “no go” decision. The developer credits the 3D conceptual cost models with giving him the facts to make a fiscally smart decision, quickly. He is also making plans to bring the technology in house to improve their internal analytics.

Fast and Accurate Cost Estimates
Keep Target Value Design Projects on Track

Target value design (TVD) is a lean construction practice that incorporates targets such as cost and LEED goals, as factors in design upfront to minimize waste and create value. For example, rather than designing a project and then determining the cost to build it, TVD methodology establishes a price first, and only then determines what can be designed to fit that price. This cost/design tension requires that designers, constructors and owners collaborate to evaluate a project's priorities, design features and costs continuously, not just at milestones.

TVD requires that the design be based on a detailed estimate. Teams composed of architects, engineers, and contractors design and construct to a specific target cost, which can never be exceeded. The target costs are established for the different areas of a project, including the site improvements, building envelope, interior/finishes, vertical transportation, material handling, structure, and mechanical, electrical, and plumbing. The targets are adjusted up and down across the different areas to maintain the overall project target cost.

Model-Based Estimating Makes TVD Work
To design to a detailed estimate, teams must have a mechanism to quickly evaluate alternate design concepts and their costs. Major projects could require new detailed estimates weekly to keep the project on target to meet its budget. Macro BIM software solves one of target value design’s biggest challenges, the need to generate fast and accurate detailed estimates for evolving designs throughout the life of the project.

Andy Hill, pre-construction manager for the Phoenix office of DPR Construction, is using macro BIM software for rapid cost feedback on a target value design project, a new university building. He says that being able to express the design concepts through a lightweight 3D model helps the team to communicate the concepts, track the budget, the changes and the issues clearly and quickly.

“During our project team meetings, I can make some changes in the model on the fly, and then we can all see it and review the cost ramifications. It keeps us clear and on track,” comments Hill.” And seeing the model helps us all to avoid errors that can creep into projects because of misunderstandings.”

As BIM technology continues to mature, construction professionals are using it to improve the existing delivery processes. The real-time connection between design, cost, and schedule using macro BIM is taking decision making and budgeting to a new level.

About the author: Lori Nash Byron is a freelance writer and owner of Practical Magic Marketing.

Lori has 20 years experience in the marketing field working in the AEC, technology and financial services sector. Visit  www.PracticalMagicMarketing.com or email Lori at lori@practicalmagicmarketing.com.


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