Las 9 Mejores Practicas para un Escaneo Laser efectivo

1. www.BDCuniversity.com BUILDING DESIGN+CONSTRUCTION MARCH 2015 43
L
aser scanning technology continues to gain momentum in
the construction industry for its ability to help Building Teams
collect tons of highly accurate information in a very short
period of time. When done right, laser scanning can prove
beneficial to all stakeholders throughout the life cycle of a project.
In the last two years, JE Dunn has performed 1,450 hours of laser
scanning data collection. Although surveying and scanning is not
our primary business, our experience in using laser scanning has
definitely helped us enhance the quality of our work and our work
processes. Here are nine things we have learned about using laser
scanning effectively in a wide variety of recent projects.
by trent nIchols, leed ap, JE DUNN CONSTRUCTION
Trent Nichols (trent.nichols@jedunn.com) is Vice President and
National BIM Director at JE Dunn Construction, Kansas City, Mo.
bim/virtual design + construction
building technology
laser scanning
JEDUNN
9 BEST PRACTICES
FOR EFFECTIVE
The rendering above depicts a 3D laser scan of a performing arts theater atrium
in greyscale format. Laser scanning can benefit all stakeholders on a project.
1. IdentIfy the intended use of the laser
scan data.
2. educate your customer on laser
scanning technology.
3. understand the physical space where
laser scanning is being applied.
4. Know the project scope.
5. determIne the required deliverable.
6. establIsh project survey control before
you start scanning.
7. collect more data than you need,
because “more is more.”
8. assess time available to deliver the
finished product.
9. fIeld a dedicated, experienced laser
scanning team.
laser scanning
BY THE NUMBERS

2. 44 MARCH 2015 BUILDING DESIGN+CONSTRUCTION www.BDCnetwork.com
1. Identify the intended use
of the laser scan data.
The first step for using laser scanning is
identifying how and at what stage of the
project the data will be utilized. Assisting
the design documentation process? Verify-
ing existing conditions? Coordinating the
mechanical trades during the construction
phases? Verifying as-built post construc-
tion? All of the above? Three examples
show how this works.
For Kauffman Charter School, a
208,000-sf addition and reconstruction
project in Kansas City, Mo., the design
team started with old as-built documents.
When our firm brought in the laser scan
data and compared it to the Revit model
provided by the design team, we discov-
ered a discrepancy between the location of
the columns in the digital model and their
actual location in the field.
For a project with Denver-based Swanson
Rink engineering consultants, an industry
leader in 3D MEP design, the client re-
quested a laser scan of its building to assist
in the development of contract documents.
By incorporating our post-processed laser
scan into the design and shop drawing
process, we were able to use prefabrica-
tion, shorten the construction schedule,
and achieve a higher-quality project.
For Saint Luke’s Hospital, Kansas City,
as-built verification was used during the
renovation. The data from the laser scan
showed the structural elements, mechani-
cal piping, duct, cable tray, and sanitary
lines that were used to build the model.
2. Educate your customer on
laser scanning technology.
Laser scanning is wonderful technology that
can help you collect a great deal of highly
accurate information in a short amount of
time, at minimal cost. But it has its limita-
tions, and you have to educate your client
as to these limitations. Your client must
appreciate that laser scanning is line-of-
sight technology: it cannot see through
walls, slabs, or ceilings. Your client must
understand that laser scanning is usually a
three-part process—data collection, scan
registration, and post-processing/model
generation; in most cases, all three must
be completed for the technology to be
useful, although there are situations where
it may be sufficient to perform only the
first two steps. (That’s where your team’s
expertise comes into play.) Your client must
grasp that laser scanning just for the sake
of scanning is of little or no value and will
result in wasted effort, cost, and data.
With a strong plan and understanding of
the technology, you can achieve substan-
tial savings for the entire project. “We have
probably saved hundreds of thousands of
dollars in [reduced] change orders due to
using laser scanning early in the process,”
according to Dave Leonard, Chief Data Offi-
cer of data center provider ViaWest. He cites
our firm’s use of laser scanning and BIM to
eliminate conflicts with mechanical pipes.
“That has been a huge benefit to everyone
involved in the process,” he says.
3. Understand the physical
space where laser scanning
is being applied.
Determine the current status of the space
needing scanning. Is it interior or exterior
space? Occupied or unoccupied? Finished
space or demolished wreckage? Laser
scanning prior to demolition can be costly
and time consuming. If planned ahead,
allowing time for scanning after demolition
can reduce the time needed for scanning
and can keep the project on schedule. La-
ser scanning reduces the time required for
field investigations as well as the number
of unforeseen conditions, reducing the risk
of rework and schedule delays during the
construction stages of the project.
4. Know the project scope.
It’s equally important to be keenly aware
of the project’s scope. The value of laser
scanning is not limited to complex mechani-
cal systems. While building the Community
of Christ Church in Independence, Mo., our
company used scanning to guide a complex
concrete paver layout installed on pedestals.
This made it possible for two crews to start
work at opposite ends with the confidence
that they would meet in the middle, which
they did. Providing a clear definition of the
scope and flexibility with the format of the
deliverable can produce opportunities and
value at all stages of the project.
5. Determine the required
deliverable.
There are various types of software platforms
used throughout the design and construc-
tion industry. If the laser scan deliverable is
going to be useful, you have to align the for-
mat of the laser scan information with your
customers’ expectations. If your designer
is working in, say, Revit and you produce
a CAD-based deliverable, it’s possible you
will lose some of the value of the service.
It would be better to deliver a Revit file. In
some cases, the design team may be more
comfortable working with raw scan data.
The deliverable can even provide added
value to the owner. We have helped owners
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On-site demonstrations of the laser scanning
process can help the client understand how the
data is gathered. Pictured: John Ochsner, BIM
Specialist with JE Dunn Construction (right),
with facility engineers Chris Carter and Tom
Jones from a confidential client firm.
bim/virtual design + construction
building technology

3. www.BDCuniversity.com BUILDING DESIGN+CONSTRUCTION MARCH 2015 45
use our laser scans to showcase their
spaces to potential tenants and occupants.
The digital model can be used for leasing,
marketing, and other post-construction
considerations. CyrusOne, an enterprise
data center and co-location provider, once
used outside marketing firms to develop 3D
models of their facilities. After utilizing our
laser scanning resources, CyrusOne was
able use the 3D scan model to lease space
in its data center in Arizona, obviating the
need for outside marketing assistance.
6. Establish project survey
control before you start
scanning.
For efficient use of laser scanning, establish
the project survey control before you do
any actual scanning; this will tie the laser
scan data into an established or common
project control. This protocol allows you to
perform additional scanning at a later date
using the same coordinate system. It also
ensures the accuracy of the scan relative to
the space, and provides a common work
point for all contractors during construction.
7. Collect more data than you
need, because “more is more.”
Once you understand the space that needs
to be scanned, the project scope, and the
deliverable required, remember this motto:
more is more. If you have “holes” in the
scan data that you collected you can run
into problems. It’s much easier to collect
that additional information while you’re
there the first time than to go back to col-
lect the missing information. To eliminate
guesswork in the post-scan process, the
more data you collect the better.
In restoring the Kansas Statehouse, in
Topeka, our firm utilized laser scanning to
assist the architect with the renovation of
the roof, perform a cross section of the
scan inside the dome, and create a scan
view looking up toward the top of the
dome. The excess data proved beneficial in
completing a smooth historical renovation.
8. Assess the time available to
deliver the finished product.
Every project has a finite amount of time
available to perform the work. The data
from laser scanning will be of little use if
it’s not available at a crucial deadline. After
reviewing the project scope, the format of
the deliverable needed, and the space that
will be scanned, you can then determine if
there is sufficient time for laser scanning.
9. Field a dedicated, experienced
laser scanning team.
Using a team that understands laser
scanning technology and is sophisticated
in the means and methods of construc-
tion processes can help ensure success-
ful results. The team scanning the project
should be familiar with the limitations of the
technology and have a firm understanding
of the project at hand. These measures
have the advantage of establishing the best
approach for the specific job, in order to
maximize value and minimize cost.
It has been our experience that laser
scanning has been most successful when
the general contractor leads the process.
Because the GC holds the subcontrac-
tor contracts, it can better manage the
full team and make the scanning output
information available on a shared platform
to coordinate all mechanical, electrical,
plumbing and technology system integra-
tions and related subcontractors. We use
our Dunn Dashboard to provide access to
all digital project data, including laser scan-
ning information, to all project stakeholders.
As the center of the construction process
with design, owners, and trade contractors,
it makes sense for the general contractor to
lead this process. +
Renderings depict two different laser scans of a performing arts theater atrium. Top: Raw point
cloud data displayed in greyscale format. This viewing method is preferred in low-light environ-
ments. Above: The same data with RGB color values applied.
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