As-built documentation is all information related to a building, construction updated after its construction.

What is as-built documentation?

As-built documentation refers to building documents that are updated and verified after construction. Scanning of the entire process and stages of the project, from foundations, pipes, and services, to completion of work.

As-built documentation is a set of data and 3D models that represent the building as it was actually built and are delivered to the client once completed.

As-built data includes all changes and additions made during the construction process, compared to the initially approved design. They usually include the exact dimensions, characteristics and geometries of all the elements of the building, as detected at the end of the work (as-build Survey). Geometric surveying can be carried out with different instruments: laser scanners, drones, total stations, etc.

To learn more about these aspects, I recommend reading the in-depth article “As-built survey: what is it and what is it for?”

It is good practice to work on the as-built documentation already during the construction phase, updating any information that has changed as you go. In this way, you are assured of generating a virtual information model that is consistent with the real one and fully complies with the contractual clauses.

 As-built documentation has many applications in the construction sector, especially for:

1.- Contractors who need updated data to demonstrate that they have carried out the works in accordance with the project.

2.- Buyers and managers of the industrial plant or warehouse who need access to all construction and assembly data (from the original design to its current state) to have greater guarantees or better manage maintenance, renovation, etc.

3.- Companies and professionals that will work in the building in the future and need updated and complete models to understand all the facilities.

4.- Banks and insurance companies that need, for example, security to guarantee mortgages and loans.

As-built documentation is necessary for any type of project. Entire buildings, facades or even individual rooms can be represented and can cover any type of work: from the renovation of the facilities of an existing building to the ex-novo design of a building complex.

Typically, the contractor is also responsible for preparing and delivering construction documentation to the client. Before delivery to the client, the documentation must be accepted and definitively approved by the designated professional.

The advantages of as-built documentation are:

Error management: linking with a BIM validation software allows you to manage and control all the IFC data of each information exchange and generate validation reports that guarantee the quality of the model;

Anomaly detection: errors are identified and corrected at an early stage to prevent problem resolution costs from becoming unsustainable;

Quality management: ensures higher construction quality as defects are identified and resolved before delivery of the work;

Compliance control: the comparison of real and virtual models allows checking compliance and updating documentation in case of inconsistencies.

Ultimately, as-built documentation guarantees greater transparency between the client and the contractor, since every detail is documented and can therefore be verified more easily.

What are the most common examples of as-built documentation?

Traditionally, the most common examples of as-built documentation have been 2D CAD drawings.

This practice is gradually evolving with the advancement of BIM methodology, increasing use of intelligent 3D models and common data environments by engineers and professionals.

A 2D CAD drawing, such as a house plan, represents the exact dimensions of each room using a line drawing. This means that the 2D plan does not contain any additional information about the elements represented (type of soil, materials, cost of the work, construction time, etc.).

A BIM model, on the other hand, is made up of intelligent parametric objects to which it is possible to associate all the information necessary for the life cycle of the work.

When managing an as-built BIM model, it is possible to select any object (a window, a pillar, etc.) and view the information associated with it. In addition, it is always possible to incorporate new information into the model or update existing information in case changes occur over time.

Therefore, the as-built model is always updated, complete and constitutes a rich container of information that can always be consulted.

However, data management can be extremely complex without an appropriate tool, as BIM data:

•  They are made up of different types of files.
•  They are usually distributed in several computer programs, which makes sharing and collaboration difficult.
•  They constantly change as the project evolves, making it difficult to keep track of all the latest changes.

The only way to manage BIM data effectively is to use BIM data management software, a cloud-based platform that helps manage BIM data in a central location, directly online and in real time.
It also ensures that all parties have access to the latest version of the BIM model, makes it easier to track changes and avoids misunderstandings and wasted time.

Why is as-built documentation necessary?

At the end of the work, the work carried out never corresponds perfectly to the design model.

This occurs because the conditions assumed in the design can change. During the course of construction, there may be budget changes, evaluation errors and unforeseen events that require redesign and redoing the work.

Even the most fluid construction process and the most advanced BIM or VDC methodology can produce a building, even minimally, different from the original design.

Therefore, it is necessary to update the design and the information associated with the real conditions, to have a model that is coherent with the built one and that is an effective digital-twin of the existing building.

In summary, as-built documentation is useful for:

• Demonstrate that what was built fully complies with the contractual conditions;
• Have an updated information model that corresponds to the actual status of the construction;
• Have a reliable basis for future maintenance work;
• Guarantee and protect the interests of clients and contractors;
• Provide professionals who will intervene in the future with updated and complete information on construction.