As-built survey and DGNB audit from one source: why the interface is the most expensive component
Anyone having an existing building DGNB-certified normally commissions two worlds. One captures: laser scanning, point cloud, drawings, room book. The other provides evidence: criteria, balance sheets, documentation for the certification body. Between the two lies an interface, and that is where the most expensive, most invisible item of the project arises.
What gets lost at the interface
The auditor needs area balances to DIN 277, dependable room data and, in the end, as-built documentation that proves the state actually built. The surveyor supplies what was commissioned, and that is rarely the same thing: areas to the wrong reference figure, a room book without the attributes the evidence requires, a model that shows the design stage rather than what was built.
Then data is requested, converted and reworked, and every round costs weeks that nobody allowed for in the certification schedule.
What changes when both come from one house
Metrika360 surveys existing buildings and accompanies DGNB certifications with its own auditor. The difference is not a marketing sentence but a flow of data: the survey is tailored to the logic of the evidence from the outset. Three examples.
The area balance stands on the same DIN 277 polygons as the room book, calculated from the survey rather than from old drawings, with a documented survey date. How that comes about is described under area calculation.
Ongoing construction documentation feeds directly into criterion ECO2.7 in the New Buildings system (2023 version), which rewards complete as-built documentation at project completion. Whoever documents the course of construction component by component anyway collects this evidence along the way rather than afterwards: construction progress documentation and as-built comparison deliver it as a by-product of site supervision.
Studies for refurbishment certification, on solar exposure or location risks for instance, arise from the same geometry the survey has already supplied, without a third party rebuilding the model.
What this means for clients
One contract instead of two trades that have to be coordinated. Short routes instead of handover loops. And documentation in which measurement, model and evidence share the same source, which in an audit is the most agreeable property of all: there is only one truth.
For the sake of precision, which belongs to the subject here: certification is issued by the DGNB. The auditor accompanies the project, establishes conformity and submits. That is exactly why the quality of the data basis is the lever on which effort and duration turn.
Further reading
- DGNB consulting – certification support based on your as-built data
- Construction progress documentation – the course of construction, component by component and dated
- As-built comparison – what was built against what was planned, with tolerance analysis
- Area calculation – the balance on which the evidence rests
- CAFM data basis – what carries on in operation after certification
Frequently asked questions
Does every DGNB certification need a new as-built survey?
No. Existing, dependable data is checked and adopted. What is captured is what is missing or cannot serve as evidence – and that check comes at the beginning.
Does this work if the auditor has already been appointed?
Yes. In that case we supply the data basis in the formats his evidence process requires. Agreeing that belongs at the start of the project, not in the closing phase.
Who certifies in the end?
The DGNB. The auditor accompanies the project, establishes conformity and submits the documents. This separation is the reason why the quality of the data basis decides effort and duration.