BIM 101: Three Basic Tools for Digital Layout

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Getting started with BIM and digital layout can seem like a monumental task if you don’t know where to start. The first step is understanding the “lay of the land” – what are the parts and pieces, and how do they fit into your business. From there, it is much easier to strategically choose a starting point that will yield the best return on the investment.

A good place to begin is with an overview of the basic equipment used for digital layout from CAD or BIM and how they work together. Three key pieces of hardware are used for digital construction layout are 1) the field controller, 2) the sensor or instrument, and 3) the prism.

Basic BIM Hardware

The field controller. This handheld device runs field software that controls the sensor or instrument. It is typically a sealed, extremely tough version of a Windows tablet enclosed in a ruggedized case so it can survive the harsh conditions on construction sites without getting broken. Look for models that feature an extra-long range Bluetooth range of about 1,200 feet (although this range varies by controller) to remotely control instruments.

The sensor/instrument. Unlike the error-prone traditional methods of tape measures, string and plumb bobs, modern total stations and laser distance meters enable contractors to measure angles and distances with precision. New technology such as 3D laser distance meters can be used to streamline the layout of new interior construction such as mechanical, electrical and plumbing (MEP) and wall partitions. Recent innovations such as the multistation effortlessly integrate laser scanning capabilities with total station measurement for as-builting, construction layout and quality assurance checks.

Prism. A prism is used to reflect an infrared or red laser beam from the sensor or instrument. Prisms are most commonly used on a “prism pole” to give them height when measuring a point on the ground or floor.

How These BIM Tools Work Together

Most contractors use a 3D model to coordinate between disciplines – i.e. mechanical, structural and plumbing – so clashes do not occur in the field. This coordinated data can be used directly in the field by adding layout points either to the model or on 2D construction documents. The data is then handed off to the field controller, which is wirelessly connected to the sensor. The instrument is oriented to align the layout data with the jobsite. From there, contractors simply start “shooting points” to replicate the accuracy of BIM in the field.

 

RELATED: See the BIM Field Trip Solutions for Concrete Layout and Quality Control

 

Once work is in place, the layout points can be “back checked” to validate that the as-built (real world) matches the as-designed (model) with real time delta reporting. When deviations are identified, the as-built points can be brought back into to the model so the impact of the deviation can be evaluated by the project team and corrective actions can be planned if needed.

This insight is invaluable for contractors. It’s like having a crystal ball that predicts constructability issues and allows them to be corrected digitally before they become change orders and schedule delays.

What tools do you use most often for construction layout? Share your comments below.

Cathi Hayes is an architect, building information modeling (BIM) pioneer and strategy leader with more than 20 years of experience developing and implementing workflow improvements in various facets of the building design and construction industry. Early on her career, she established Revit as an industry changing model-based design technology in the architectural design industry. She later served as strategic BIM manager for Autodesk, establishing the company as a primary resource in the US residential, commercial and government markets for design, engineering and construction collaboration to help improve workflows and reduce costs. As BIM strategy and business development director for Leica Geosystems, Cathi focuses on helping building contractors achieve greater success in BIM through the adoption of leading-edge hardware and software solutions that make it easy to move from 2D to 3D workflows and extending the value of BIM into the field. Cathi is a trusted BIM advisor and a leading voice on BIM throughout the North American construction industry. She holds degrees from North Carolina State (BEDA Architecture) and the University of Kansas (PBA). She can be reached at cathi.hayes@leicaus.com.

3 comments

  1. Pingback: Leica Geosystems Launches New BIM Field Trip Solutions for Contractors - BIM Learning Center

  2. Pingback: Digital Layout Saves Concrete Contractor $2,000 Per Week - BIM Learning Center

  3. Pingback: BIM 101: How to Prep Model Data for Field Layout - BIM Learning Center

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