We know what blueprints are and some of us are even familiar with pencil and paper sketches.  In the building industry, the client has a vision and the best way for the builder to translate that vision into a reality is by using the blueprints - whether a sketch or full set of drawings (specs included).   This is a good system as far as communicating the vision, but what about the conflicts that no-one can see before the first survey stake is slammed into the dirt?

In this current erra of technology advancements where doctors are performing surgery on the human eye with lasers to make our vision better, isn't there something that the construction industry can do to make our jobs run with fewer conflicts and at lower costs?  The answer is yes.  BIM.

Building Information Modeling (BIM) is like building with block, but in the digital arena.  These blocks are better understood and components of the intended structure.  But more than that, these components provide an opportunity to bridge the gaps in engineering and design as each element of the building is constructed to make a whole before the project ever reaches the bidding process.{snippet contentgooglead-box-right}

What does that mean for the contractors. 

We can think of a few:

1. Lower Errors & Omissions:  No more concerns about duct-work going through a door header, or plumbing going through a portion of a concrete beam congested with rebar.
2. Fewer errors = Faster building.
3. Faster Building = Increased efficiency.
4. Bidding is fast and accurate as the modeling "knows" what it is.  A wall knows it's a wall and what is required to make it a wall and as such can be scheduled or quantified.

As a builder with some design work under my belt and hundreds of hours 'negotiating' change orders, I was intrigued by the idea of benefiting on both faces of a project: the front (estimating) and back (Construction) ends of the BIM solutions. 

Let's face it, estimating is an pocket with a hole in it.  We pour tons of money into it only to retain a small portion in return.  It is a necessary evil that is one of the least rewarding yet most expensive (assuming all projects are run efficiently).  Based on current economy conditions, the conditions of estimating change with a detla that separates the highs and lows.  We've seen the market sway to a point where the first one to the job wins with 'name your price' bids and on the other end of the extreme where it doesn't matter how long you've been in business or how comfortable the client is with your firm:  He wants the bottom dollar price and you don't have it.

In the commercial arena, I've sat through too many moments of anticipation waiting to hear who the announcement of the "lowest qualified bidder" on a project where we've invested a gross amount of time and energy only to find that some idiot bid 10% lower than the 3 lowest bidders - and he gets the job.  I often asked myself how we could 'level the playing field' so that "lowest qualified bidder" actually meant "qualified".  Not missing something or omitting something because of expectations, but "like for like" and "apples to apples" qualified.{snippet contentgooglead-rectangle-left}

We all estimate the same.  We see the drawings, digitize, measure, or in some way, perform our takeoff based on a flat piece of paper that we've checked the scale on.  Some of us use electronic plans with software to quantify our jobs.  These methods, as you have likely already realized, are prone to errors and propagate inaccuracies there may be in the original drawings.  By using a building information model instead of drawings, the takeoffs, counts, and measurements can be generated directly from the model.  Information is always consistent with the design even during a change.  For example, if a window size is changed to a smaller window, the change automatically trickles down to all the related construction documentation, schedules, and takeoff measurements used by the estimator.

While we all eagerly perform takeoffs on value engineering as a way to preserve our potential win, we also do it grudgingly because we know we need to revamp our estimate and realize up front that the modifications to the plan will ultimately produce confusion during the construction process.  Further, the time to change a bid is putting more money into the pocket with holes. 

If a manual takeoff is not required, you can save time and cost while reducing the number of errors by using the BIM process.  In fact, why waste the talent and expertise of estimators who are simply counting or quantifying?  

By automating tedious tasks, BIM allows estimators to use that time to focus on other elements of the project like assemblies, generating pricing, factoring risks, establishing methods and staging.  This means better use of time, more competitive bids, and a better project setup for the transition into the hands of the construction management team.{snippet contentgooglead-box-right}

So how does it work?

According to Autodesk’s white papers, the building information model provides many ways of getting the quantities and material definitions out of a project.  Broad categories of integration include:

• Application Programming Interface (API) to commercially available estimating programs from vendors such as U.S. COST or Innovaya (which then integrates with Sage Timberline Office Estimating). This approach uses a direct link between the costing system and Revit. From within Revit, a user exports the building model using the costing program’s data format and sends it to the estimator, who then opens it with the costing solution to begin the costing process
• ODBC connection to estimating programs such as CostX or ITALSOFT - popular Australian and Italian cost estimating solutions, respectively. ODBC is a tried and true standard, useful for integrating data-centric applications like specification management and cost estimating with building information modeling. This approach typically uses the ODBC database to access the attribute information in the building model, and then uses exported 2D or 3D CAD files to access the dimensional data. Part of the integration includes a reconstitution of the building data within the costing solution – linking cost geometry, attributes, and pricing.
• Output to Excel.In comparison to the approaches outlined above, quantity takeoffs done within Revit and output to a Microsoft® Excel® program may seem lackluster, but the simplicity and control is perfectly suited to some costing work-flows. For instance, many firms just create material takeoffs in Revit, output the data to a spreadsheet, and then hand it off to the cost estimator.

There are no right or wrong approaches – each integration strategy is based on the estimating work-flow used by a specific firm, the costing solutions they have in place, the pricing databases they use, and so on.{snippet contentgooglead-rectangle-left}

About Revit

The Revit platform is Autodesk’s purpose-built solution for building information modeling. Applications such as Revit® Architecture, Revit® Structure, and Revit® MEP built on the Revit platform are complete, discipline-specific building design and documentation systems supporting all phases of design and construction documentation. From conceptual studies through the most detailed construction drawings and schedules, applications built on Revit help provide immediate competitive advantage, better coordination and quality, and can contribute to higher profitability for architects and the rest of the building team.

At the heart of the Revit platform is the Revit parametric change engine, which automatically coordinates changes made anywhere — in model views or drawing sheets, schedules, sections, plans… you name it.

For more information about building information modeling please visit us at http://www.autodesk.com/bim. For more information about Revit and the discipline-specific applications built on Revit please visit us at http://www.autodesk.com/revit.

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