In short
As-built drawings record a building as it actually stands, not as it was designed. They are produced by surveying the building and drawing what exists: plans, sections, elevations, structure and services. Authorities rely on them in legalization, and owners rely on them for every later repair, extension and sale.
Key points
- Design drawings show intent; as-built drawings show reality.
- For an existing building they are produced from a measured survey and inspection.
- They cover plans, sections, elevations, structural elements and, where needed, services.
- Accuracy matters: an authority, a buyer or a future engineer will rely on them.
A building’s drawings describe what it was meant to be. Over time, what it actually is drifts away: changes during construction, a room added later, a wall removed, services rerouted. As-built drawings close that gap.
Design versus as-built
Design drawings show intent: what the architect and engineers designed and the authority approved. As-built drawings show reality: what stands on the plot today, measured and recorded.
How they are produced
For an existing building, as-built drawings come from a survey:
- Measurement of rooms, walls, openings, levels and the plot.
- Inspection of the structure: columns, beams, slabs, and how additions connect to the original building.
- Services, where needed: routes and positions of the main installations.
- Drawing the result as plans, sections and elevations, with notes on what could not be verified.
Why legalization depends on them
An application to regularise works asks the authority to accept what exists. The as-built drawings, with the technical reports that accompany them, are how the authority sees it. Errors cause comments, delays or, worse, an approval that does not match the building. Preparing technical drawings and reports is part of Nation’s legalization service.
Why owners need them anyway
Every future repair, extension, safety report or sale goes faster with accurate drawings. They are one of the most useful documents an owner can keep.
Questions
My villa has its original drawings. Are they as-built?
Not necessarily. Changes during construction and later works are often not reflected. A survey shows how far the drawings match the building.
What if there are no drawings at all?
Then the building is surveyed and drawn from scratch, with the inspection filling in what cannot be measured directly.