Taking Budgeting to a New Level with 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.
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
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
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
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 email@example.com.