There are many types of architectural documentation including construction drawings, feasibility plans, demolition plans, permit plans, mechanical plans, electrical plans, space plans, elevations, sections, renderings, and BIM models etc. Generally speaking, such documentation is developed to indicate design intention; that is, how a designer, architect, or engineer intends for a building or space to be built in advance of construction.
Of course, intention and real-world construction are two different things and there is almost always a disparity between design documentation and how real buildings are actually built. Construction skill, technique, materials, change-orders, tenant activity, and evolving mechanical implementations can cause a building to veer away from original design intent, either during construction or at any point during the building’s operational lifecycle.
In short, design and construction documents rarely (if ever) match real world conditions after the fact.
As-Built drawings and models represent a building or space as it was actually constructed. As-built documentation is developed after construction (or a particular phase of construction), either immediately or at any time following. As-built drawings and models are developed by physically measuring the existing facility for the purpose of developing CAD or BIM documentation. Extreme Measures uses precision laser distancemeters and 3D laser scanners to measure physical space in addition to a variety of CAD and BIM software packages to draft and model the space.
There are numerous use-cases and reasons for developing as-built drawings and models. Landlords and building owners are interested in as-builts for lease area audits, facility management activities, and asset tracking. Architects and engineers use as-builts to understand existing conditions prior to renovation or retrofit. Fabricators and installers require precise as-built data so that they can fabricate to spec off-site and to identify spatial constraints (clash detection) in advance of installation.
For older facilities, existing documentation is often outdated or lost altogether. For newer buildings, determining as-built information sets a baseline for building operations and planning moving forward. Either way, buildings are likely to change over time and diligent stakeholders should ensure that as-built documentation is maintained and up-to-date.