AS-BUILT – WHAT DOES IT MEAN?

“As-built” – anyone involved in architecture and the construction industry will sooner or later come across this term. It is almost always linked with documentation. But what does as-built documentation actually comprise? How is it created and what is it needed for? There is no legal or regularitory definition of the term. Even within the industry, there may be different opinions when it comes to the definition and scope of a as-built documentation. Despite this, or rather precisely because of this, we will try to clarify all the questions surrounding as-built documentation in this article.

As-built documentation vs. construction drawing - what is the difference?

As-built documentation is documentation of the actual state of a building or construction project. A construction drawing, on the other hand, shows the planned state of a project. Anyone who has already been involved in a construction project knows that there can be considerable differences between the planning and the result. In order to obtain realistic documentation of the project, it is necessary to carry out as-built documentation in addition to the construction drawing.

Starting as early as possible: Documentation of construction progress

So does it make sense to simply create as-built documentation after the project is finished? Of course, the finished project should be fully documented. However, it is even better to start much earlier. Especially with larger projects, it is advisable to document the various stages of the construction progress. There are several reasons for this. On the one hand, it allows all those involved to be kept up to date on the progress of construction.

Even more important, however, is the comparison with the construction drawing and the planning. This way, possible complications can be recognized at an early stage and dealt with accordingly. After each construction step, costs can be adjusted if necessary, new permits can be obtained, materials can be exchanged, the statics can be recalculated, and so on. This makes it easier to avoid unpleasant surprises and cost explosions.

Of course, final as-built documentation should also be carried out after the project has been completed, and it is also worthwhile to acquire it for already existing structures. On the basis of the as-built documentation, subsequent conversion measures or installations can be planned and carried out. In addition, it provides important information for disaster control and rescue forces in case of an emergency.

How is as-built documentation created?

The purpose of as-built documentation is therefore clear. The question that arises next is how it should be carried out and what exactly it should contain. Regardless of whether the construction progress is to be documented or a project that has already been completed, the first thing to do is to create a accurate reality capture. Nowadays, depending on the size of the project, this is done by means of laser scanning and/or drone flights. If you work with a laser scanner, it generates a point cloud that must first be processed and evaluated with special software. Point clouds can also be generated from drone flights with special software such as Pix4D. With our Origins software for example, sections, floor plans and much more can be quickly created from the point cloud data. Data processed in this manner can then be imported into the CAD system, where a model of the project is created.

But a reality capture and a simple 3D model are often not sufficient for as-built documentation. Depending on the requirements, further information must be included in the documentation and there is also a lot to consider when creating the 3D model.

For instance, the level of detail, or LOD for short, plays an important role in 3D modelling. For example, should the valves of water systems be modelled down to the smallest detail or is it sufficient to roughly represent them in the correct position and orientation? Such questions should already be clarified and discussed with the modeller before the documentation is created. The modeller can determine in a personal conversation which LOD level is required for your project. There is no industry standard for the accuracy of as-built documentation. This is not least due to the fact that a higher degree of accuracy is associated with additional costs, which of course one does not want to bear if it is not needed for the project in question.

Another point that must be taken into account is additional information. For example, should the material of the floor, doors, windows, etc. also be documented? Which window model is used? Should invoices and static certificates be stored? These questions must also be clarified and the scope must be determined before preparing as-built documentation.

Ultimately, the scope and accuracy of as-built documentation always depends on your individual requirements. In general, however, it can be said that at least a rough digital reality capture by means of laser scanning is always useful.This way, errors can be avoided in the construction phase and possible subsequent construction work can be implemented more easily.

Do you have any further questions about as-built documentation or point cloud evaluation? Then write to us or call us under: +4971539295930.

Our support team will be happy to advise you!