Accurate 'as-builts' worth their weight in gold

New technologies can help provide building owners with accurate and accessible drawings and specs

September 01, 2002 |

In the famous Hollywood thriller Die Hard, police help actor Bruce Willis defeat a group of terrorists who have taken over a luxury high-rise office. In the movie, building owners are able to produce the drawings and specifications of how the building is actually built and offer them to the police. For many high-rises today, that scenario might as well be science fiction.

More like reality, say many designers, contractors and facility managers, is bundles and boxes of original drawings and specifications stashed somewhere in seldom-used office space. And whether these reams of paper are complete or neatly put away in any kind of accessible or sequenced arrangement is anybody's guess.

The drawings and specifications that describe the actual layout, structure, materials and systems of a building are what owners describe as the "as-builts." Roughly equivalent to a cross between the instruction manual that's kept in a car's glove compartment and the more detailed manual that a technician uses to repair a car, these documents are the paper or digital representation of a building. As the construction industry inches toward becoming a sophisticated creator and user of up-to-date project data, the quality of a project's as-built drawings and specifications increasingly reflects the participants' effective use of computer technology.

Construction technology experts often say that a good set of as-builts can literally be worth its weight in gold for the information that it provides. Accurate project data serve designers, contractors and consultants in a wide variety of ways during the project, as well as the ultimate end users of a facility, especially those deeply engaged in automated facility management.

To achieve improved collaboration, integration and communication, project users absolutely depend on correct project data. For example, on a project where team members are using a 3-D model as the central repository for project data, an up-to-date as-built of a project can eliminate scores of expensive and time-consuming project mistakes and delays. Whenever project questions arise, users simply punch up the latest answers. Project changes that once led to delays and sometimes lawsuits between designers, contractors and owners are averted.

Once a facility is up and running, information becomes an increasingly critical part of its life cycle. Facility managers with accurate information can save owners money on the operation of mechanical, electrical and other systems because they know exactly how the building is designed. They can also save on the maintenance of the building, and are better able to bring future facility remodelers up to speed without a lot of exploratory demolition or inflated bid prices due to the extent of the unknowns on a project.

Yet despite these benefits, the industry is rife with projects full of undocumented changes. Still not convinced of the substantial long-term value that accurate and complete as-builts provide, developers and other owners procure buildings with a weak set of guidelines. It's still very common to have building owners discover how much they don't know about their new facility and how it is built soon after it is delivered.

Accurate as-builts should be part of the contract

Taking responsibility for as-builts is one of the "hot potatoes" of the construction industry. An architect, contractor or project consultant may be contracted to do it, but just how accurate and thorough the actual creation is depends ultimately on the owner's oversight. A big part of the problem comes down to labor — who is responsible for not just inspecting the project, but also recording the correct locations where changes to the latest design intent have taken place.

One way around it, says Wayne Shannon, owner of Computer Graphics, Atlanta, is to require consultants that create as-builts to be paid by the contractor, rather than directly by the owner, as part of the contract. When contractors are responsible for creating a full set of as-builts before they get their last payment, the thoroughness and quality of the information provided tend to be higher.

Unfortunately for many owners, when the need arises to refer back to the drawings and specifications for a project, the situation is a difficult one. With CD-ROM technology, the information on drawings and specifications can be made easily available by putting it on a handful of searchable, usable disks. Computer Graphics, for example, is frequently hired by owners and contractors to take the paper mess of a project, scan it, and deliver back an ordered set of CDs filled with Portable Document Format (PDF) files of that paper.

If the as-builts need extensive work, the situation becomes even more difficult. The original project staff that know the ins and outs of the building have moved on to other projects with other companies. On historical renovation projects, the predicament is a given, and finding anything written about how the building is built is often just a stroke of luck.

Laser scanning

In both cases, building owners are turning to a small but growing industry of as-built creators. Utilizing technology popular in the process plant industry, in which miles of detailed pipe work often require dead-accurate rebuilding in record time, photogrammetrists and laser-scanning experts create CAD drawings of existing structures with either a detailed study of high-resolution photographs, or by collecting and analyzing millions of data points via a laser-powered measuring system.

Reflecting the growing popularity of laser-scanning technology, at least three laser-scanning vendors exhibited at the A/E/C Systems show, Anaheim, Calif., in June: Toronto-based Optech Inc.; Norcross, Ga.-based Mensi, and San Ramon, Calif.-based Cyra Technologies. Cyra has in recent years helped popularize the use of lasers with its Cyrax system, a tripod-mounted laser scanner attached to a computer equipped with special process software. The laser scanner gathers 3-D point "clouds" and creates 3-D surface geometry of complex structures and sites. Rather than being stuck with running specialized scan-reading software, users can turn to a newly introduced add-on program called Cloudworx that allows them to import that data into AutoCAD or MicroStation design programs. While also used in the process industry, the firm's technology has been used recently to survey the accuracy of a elevator core under construction on an office tower in Phoenix.

Ultimately, improved data-gathering techniques via technology can solve some of the problems of creating as-builts. But a bigger stumbling block for as-built accuracy and thoroughness remains. The still-prevalent digital disconnect between designers and contractors, as well as between contractors and facility managers, means paper-based communications will be around — and inaccurate — for some time to come. In the meantime, another service provider will still find work in the industry. Owners still engage legal consultants who specialize in creating accurate as-built specifications and drawings. Unfortunately, their goal is often to support an "as-designed vs. as-built" lawsuit.

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