Laser Scanning: The New and Improved Tape Measure

By: Samantha Oshea, Harper General Contractors Virtual Building Intern

“What new technology does is create new opportunities to do a job that customers want done.”

-Tim O’Reilly

Benefits of Laser Scanning

A large percentage of the construction industry involves adaptive reuse – taking the old and making it new again. The construction industry has found huge benefits and success in the use of laser scans in order to help complete these projects.

What is laser scanning?

Traditional methods of data collection, used to understand the as-built conditions of a building, involve weeks of labor exerted by men and women who travel to the job site to document measurements and locations of the existing structure. Laser scanning takes away the manual labor and integrates technology to accomplish the same task. It involves collecting surface data with the use of high-speed lasers combined with a camera and color coding to capture the distance of distinct points over a given area. For example, the laser scan can determine where structural beams and columns are located, as well as the distance between the floor and ceiling and all other fundamental features. The information about the existing elements in a building captured through the scan are extremely precise with error margins of less than 1/8 inch. The data can then be used to produce a 3D model that is valuable for computer-aided design, modeling, and building information modeling.

How does laser scanning help renovate historic buildings?

Blueprints of historic buildings are often inaccurate or become lost overtime. This makes the restoration process of that building much harder and time-intensive. Steve Foushee, Harper Senior Project Manager, says, “The largest challenge of working with historic renovations is matching handcrafted items to what we have now.” In other words, the actual structure is often not consistent with the drawings, measurements and blueprints that may be available. Foushee explains that having a scan of the existing building helps with the matching of those architectural drawings to the as-built structure.

Harper recently renovated downtown Greenville’s Christ Episcopal Church, consecrated in 1854. A laser scan of the 150-year-old church was performed in order to effectively coordinate the exposed sprinkler system in the sanctuary, identify the structural constraints in the basement, and manage the installation of the mechanical, electrical, and plumbing systems. “When scanning the church, we found that the actual building was not square. We also found some of the walls were six inches off from where they were shown on the design drawings,” says Timothy Lewis, Harper’s Director of Virtual Building.

What are other benefits of this technology?

Using laser scan technology has proven to significantly cut the time of survey measurement, taking only a matter of a few hours to a few days to get the correct measurements for the entire structure. The technology also minimizes rework expenses to 1 – 3% of the total cost of construction, a strong decrease from the original 12 - 15%. This reduction ultimately translates into hundreds of thousands of dollars in savings, in addition to keeping the project on schedule. Laser scans produce higher precision data and have the ability to generate measurements accurate within a 1/8 inch deviation. This results in better information management, less physical site visits, and increased visibility and understanding of the site.

The advancements in the construction industry due to laser scan technology have been significant and positively impactful. As the technology continues to progress, our industry will continue to improve, resulting in better and faster completion of projects.

For a more in-depth look, watch our video of how Harper uses Building Information Modeling in Historical Renovations and New Construction:
“An ounce of prevention is worth a pound of cure.”

- Benjamin Franklin

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About the Author:

Samantha Oshea started with Harper as an intern last May as a Virtual Building Coordinator. Before this, she served in the United States Marine Corps as active duty where studied to be a Ground Radio Repair Tech while living in Japan during her enlistment. She exited as Corporal some years later and joined the Navy reserves as an admin and was the support for Seal Team 17.