What You’re Missing When You Don’t Evaluate “As-built” Conditions

An effective construction plan for a renovation or retrofit project has to start with at least some concept of the site’s current condition. Unlike a brand-new building where limits on the design are less severe, a renovation or retrofit project has much tighter constraints with pre-existing conditions on which all aspects of the job must conform to.

Additionally, if the structure you’re going to be working in is a historical site that needs special consideration, or if the building materials are less than ideal (but can’t be easily swapped out), the need for thorough and detailed information becomes even more acute.

But how can the most detailed and accurate “as-built” information be obtained in a cost-effective and efficient manner without eating up the entire project’s profit margin in the process? The key is the strategic leveraging of technology.

The necessary first step in the planning and layout of a renovation or retrofit project

When an estimator is putting together a bid for a renovation or retrofit project, having access to general measurements, material lists, and configurations (such as what they could get from generic paper blueprints) is usually sufficient.

However, once more thorough job planning commences, designers and detailers are going to need highly accurate measurements of the as-built condition if they’re going to be able to plan an efficient and cost-effective job. The following options for getting this information tend to fall short for a number of reasons:

Manual layout measurement

The measurement of a large space for layout and design purposes can be handled in a number of ways. Traditionally, two guys with a tape measure and a clipboard can map out the basics of a space over the course of several hours. Combining their efforts with detailed images, schematics, and blueprints, the designers working on the renovation plan should be able to pull together enough data to do what they need to do.

Inevitably, in this kind of scenario, human error creeps in, measurements need to be confirmed and/or redone, and some ambiguity remains. The result is either a longer-than-necessary planning/design phase involving multiple measuring projects or a list of preventable errors or changes occurring onsite once the project commences and it becomes obvious that some details of the plan are based on inaccurate measurements.

The use of more modern devices, such as laser distance measurers and inclinometers can certainly help, both in speed and accuracy, but it still remains very much a manual process. Anywhere a human being is involved, there’s the potential for human error.

Moving back and forth between 2D and 3D design plans

In the modern era of BIM construction, the use of 3D models throughout the building process is becoming more and more common. However, it hasn’t supplanted 2D drafting work completely, and, at least in some disciplines, it has a long way to go. So, the modern construction project often requires a lot of back-and-forth collaboration using 2D and 3D versions of the needed plans.

When a construction firm is caught between advanced 3D BIM design work being done in the office and a field crew that relies on traditional 2D plans, a number of inefficiencies and room for error are created. Likewise, when different trades need to work concurrently to meet a tight deadline, but one’s following a 2D plan and the other’s using a 3D model, collaboration may be difficult.

The end result is more required back-and-forth discussion between the design team and the field, more errors and rework needed at the jobsite, and potential safety or performance issues becoming part of the completed project.

In just these two examples, it’s easy to picture money being siphoned right off the top of the already-thin profit margin as hours are wasted. Many other similar scenarios exist. But what you really came here to learn is how to avoid these time- and money-wasting issues and get that profit back.

What technology tools are available to solve these issues?

The more accurate the “as-built” information you have at your disposal on a project, the better. But the issues noted above with human error can still occur and waste untold amounts of money over the course of a project. They can, however, be solved fairly simply and quickly with a comprehensive 3D laser scanning solution for BIM by using both hardware and software tools.

Capturing the data: 3D Laser Scanners

Automated 3D laser scanners have become the gold standard in the construction trades to capture a highly accurate data of as-built conditions — including precise measurements, inclines, and color images — without allowing human error to interfere in the data collection process.

These machines combine powerful laser-scanning technology with internal measurement computation and image capture to create detailed point cloud representations of a given space. These point clouds can then be processed and exported to CAD programs or other BIM software to develop 3D models.

Translating the data: Point Cloud Modeling Software

While the output from a quality 3D laser scanner is impressive, it’s not able to be put to use just yet. The millions of points and measurements captured by the scanner need to be translated into something designers and detailers can use if they’re going to have any value.

Point cloud modeling software fills that need. It enables you to register, visualize, explore, and manipulate as-built data collected from your 3D laser scanner. These applications take the powerful and accurate data collected by the scanners, and translate it into BIM- or CAD-ready 3D models that can be imported to any design software for estimation, planning, designing, or detailing work.

Most importantly, they do so quickly, intuitively, and — to some extent — even automatically. This reduces labor costs above and beyond the time and cost savings realized by avoiding the errors and inefficiencies described earlier.

So, don’t head into any renovation or retrofit project without thorough and accurate “as-built” data you can rely on. But don’t break the bank or take forever gathering it either. For a more detailed treatment of 3D laser scanning, read our free guide: The Evolution of 3D Scanning.