Level of Information Need (LOIN): how much information is enough
LOIN (Level of Information Need, in German Informationsbedarfstiefe) is the standardised approach of defining a model’s information requirement from its intended use: who needs which geometry, which properties and which documents, for what and at what point in time. The governing standard is DIN EN ISO 7817-1 (2024 edition), which replaces the withdrawn DIN EN 17412-1.
The difference from thinking in levels of detail
“Everything in LOD 300, please” is a common order and rarely the right one. It sets one level of detail for the whole building, although the purpose varies from area to area. The result is a model that is too coarse in one place and too expensive in another.
The level of information need approach turns the question around. The starting point is not the level but the use: what is the model needed for, who works with it, and what must be findable in it? From this follows which geometry is needed, which properties are attached to it and which documents belong with it.
The two are not mutually exclusive. In practice they run side by side: the level of detail per discipline as a short common language, the level of information need as the actual agreement.
Why this is decided before the capture
An as-built survey can be refined afterwards as long as the point cloud is available. What cannot be created afterwards are properties that nobody recorded on site: rating plates, years of construction, condition data, assignments. Anyone who needs them later needs a second site visit.
That is why this definition comes at the beginning and not at acceptance. It determines both the effort and the usability.
What it achieves in a tender
It makes quotations comparable. When the level of detail per discipline, the scope of attributes and the target documents are named, everyone bids on the same service. Without this definition, prices differ by multiples, and none of the bidders has lied.
Frequently asked questions
What does LOIN stand for?
Level of Information Need, in German Informationsbedarfstiefe. The information requirement is defined from the intended use, both geometric and alphanumeric, instead of by a blanket level of detail.
Which standard applies?
DIN EN ISO 7817-1 in the 2024 edition. It replaces the withdrawn DIN EN 17412-1 of 2021, which covered the same subject as a European standard.
Does LOIN replace the LOD levels?
It supersedes blanket thinking in levels, but in practice it does not displace them. The usual approach is a combination: the level of detail per discipline as shorthand, the level of information need as the agreement.
Who defines the information requirement?
The client, derived from the purpose and from the data model of the target system. We support this because the definition determines effort and usability, and we record it in writing before the capture.