The Use of Imagery in As-Built Documentation
They say that a picture is worth a thousand words, but in the realm of as-built documentation a picture can be worth thousands of dollars. Images taken during construction and preserved as part of the as-built record can save building owners and facility managers thousands of dollars on maintenance and repair over the lifetime of a building.
Images can come from a variety of sources such as smart-phones, digital cameras, point-cloud viewing software or Building Information Modeling software. To be useful, an image must have high enough resolution to show the details of interest, and it’s location within the building must be known with enough precision to insure that the image includes the subject of interest for a given maintenance or repair task.
This paper will discuss trends in the acquisition and use of digital imagery for documentation of new and existing buildings. Examples of combining images from photos, point clouds, and BIM models will be used to help explain the advantages and disadvantages of each type of imagery. Simple models of digital imaging will be presented that relate image resolution to camera to subject distances. Guidelines for RFQs and RFPs for digital photography will also be discussed. These guidelines are being developed under the direction of the USIBD standards committee.