The Quality Assurance for Building Act (Wkb) has applied since 1 January 2024. For new buildings in consequence class 1, such as single-family homes and smaller commercial buildings, the municipality no longer checks the building technology in advance. An independent quality assurer checks during design and on site whether the building meets the rules.
For the structural engineer and the building consultant, it is mainly the surroundings that change. Your calculations and drawings go to the quality assurer and into the file at handover. The contractor is liable for defects not discovered at handover. If the cause lies in your calculation, the contractor will pass that damage on to you.
In short
- The Wkb has applied to consequence class 1 since 1 January 2024. Until the end of 2028 it is expected to cover only new construction of simple buildings. Other buildings and renovations will follow later.
- The contractor is liable for defects not discovered at handover, unless they cannot be attributed to the contractor (Civil Code 7:758(4)). The law does not mention the consultant, but the contractor can recover damage from a calculation error from you.
- Deliver calculations on time and complete, update them to what was actually built, and record in the assignment who oversees the coherence of the structure. DNR2025 asks parties to record this in advance.
In this article
- What is the Wkb, and which buildings does it apply to?
- What changes in the building process for the structural engineer?
- Who is liable for a hidden defect in the structure?
- Which of your documents go into the file at handover?
- What does DNR2025 say about structural safety and the Wkb?
- Can you act as quality assurer on a project yourself?
- Is private quality assurance something specific to the Netherlands?
- What do you arrange in your assignment under the Wkb?
What is the Wkb, and which buildings does it apply to?
The Wkb is the law that shifts supervision of building technology from the municipality to an independent quality assurer. It has applied since 1 January 2024, at first only to buildings in the lowest consequence class. The national government gives single-family homes and smaller commercial buildings as examples (Government of the Netherlands, Quality Assurance for Building Act).
A consequence class is a grouping by the consequences if a building fails. Consequence class 1 is the lowest. You can check whether a project falls under it via the Omgevingsloket (the national environment and planning portal). According to the government, the changes are expected to apply until the end of 2028 only to new construction of simple buildings. Other buildings and renovations follow after that (Government of the Netherlands, Wkb).
The quality assurer is an independent person or organisation that works with an approved quality assurance instrument. The assurer checks whether the building meets the technical rules in the Buildings (Living Environment) Decree (Explanatory notes to DNR2025, definitions).
What changes in the building process for the structural engineer?
Your work is looked at earlier and more often. Based on the building plan, the quality assurer draws up an assurance plan with the contractor. The building notification with the building plan and the assurance plan must reach the municipality no later than four weeks before construction starts (Government of the Netherlands, Wkb).
During construction the quality assurer keeps an eye on things. If the assurer sees a problem, it is reported to the client and the contractor. Afterwards the client submits to the municipality the drawings and calculations of the building as built, together with the quality assurer's statement. Two weeks after that completion notice the building may be used (Government of the Netherlands, Wkb).
For you this means three things. Your calculations must be ready before the building notification is sent. Changes during construction must be reflected in your calculations. And at the end your documents must match what is actually there, because the completion notice relies on them.
Who is liable for a hidden defect in the structure?
The contractor. Since the Wkb, the contractor of a building is liable for defects not discovered at handover, unless they cannot be attributed to the contractor. With a private client this cannot be departed from. With a business client only if it is expressly stated in the agreement (Civil Code 7:758(4)).
A legal claim about a defect in a building is time-barred in any case twenty years after handover (Civil Code 7:761(2)). How long a roofing business stays liable for a leaking roof is covered in a separate article.
The law does not name the structural engineer or the building consultant. Your liability runs through your own assignment. That assignment carries the duty of care of a good contractor for services (Civil Code 7:401). If the contractor is held liable for a defect that stems from an error in your calculation, it is likely that the contractor will recover that damage from you. That is a consequence of the chain, not a separate rule in the Wkb.
If you work under DNR2025, your own liability stays limited to the fee up to a maximum of € 1,000,000, or three times the fee up to € 2,500,000 if you agree that in writing (Explanatory notes to DNR2025, article 14.9). The contractor does not have that limitation towards a private client. The difference is borne by the contractor.
Which of your documents go into the file at handover?
When reporting that the work is ready, the contractor must give the client a file. It contains at least drawings and calculations of the building and the installations, a description of the materials and installations, and the information for use and maintenance (Civil Code 7:757a).
That file must give full insight into how the contractor has performed the agreement. Your structural calculation and your drawings therefore belong in it, in the version as built. Agree with the contractor or the client when you deliver that version and who passes on changes during construction to you.
What does DNR2025 say about structural safety and the Wkb?
DNR2025, the standard terms of BNA and NLingenieurs, has a separate chapter on it. The client appoints one person with final responsibility who oversees the coherence of the structural design, for example a lead structural engineer. Before the start, parties record in writing who has which tasks for structural safety (Explanatory notes to DNR2025, articles 10.1 and 10.2).
The explanatory notes give an example. A structural engineer calculates the load-bearing structure and a second consultant works on the façade fixings. Without someone who oversees the whole, a crucial detail can go unnoticed. The explanatory notes link this to the Wkb and the Buildings (Living Environment) Decree (Explanatory notes to DNR2025, article 10.3).
If you are responsible for structural safety, a heavier duty to warn applies. You warn the client if you see defects or contradictions, or if a reasonably competent consultant should have seen them, in data or contributions from others that affect the structure (Explanatory notes to DNR2025, article 10.4). Record such a warning in writing.
Can you act as quality assurer on a project yourself?
Yes, but not on a project you design or work on yourself. The quality assurer must be independent of whoever designs or builds the building. According to the explanatory notes to DNR2025, the consultant may not be designer or supervisor at the same time in the same assignment (Explanatory notes to DNR2025, article 11.1).
If you act as quality assurer, DNR2025 limits your responsibility. You are not liable for someone else's design, the execution, the final building quality or obtaining permits. That changes only if the damage comes directly and demonstrably from your own assurance work (Explanatory notes to DNR2025, article 11.2).
Is private quality assurance something specific to the Netherlands?
No. Research on seven European countries shows that control of buildings increasingly lies with private parties, with checks spread across the whole construction process. The researchers found that the emphasis is on the safety of complex structures, and that far fewer requirements are placed on the quality of the builders themselves (Meijer & Visscher, 2017).
The study is a desk comparison from 2016, not a measurement of the Wkb in practice. It does show why the Wkb puts the emphasis on who delivers what and when. For the structural engineer the lesson is practical: what you cannot show does not count in an inspection or a claim.
What do you arrange in your assignment under the Wkb?
- Ask whether the project falls under consequence class 1 and who the quality assurer is.
- Agree dates for your calculations that fit the building notification four weeks before the start.
- Record who oversees the coherence of the structure, and which parts you do not calculate.
- Agree how changes during construction reach you, and what updating drawings and calculations costs.
- At the end deliver the as-built version, and keep a record of what you delivered and when.
- Check that your professional liability insurance covers your type of work and the agreed cap.
Point 4 is also a pricing question. Updating documents to the as-built version is work that was often not asked for in the past. List it separately in your quotation, and you avoid discussion about extra work at the end of the project.
Sources
- Government of the Netherlands, More supervision in construction through the Quality Assurance for Building Act (Wkb) (in Dutch), accessed 31 October 2026. rijksoverheid.nl
- Dutch Civil Code Book 7, articles 401, 757a, 758 and 761, in force from 8 October 2026 (in Dutch). wetten.overheid.nl
- BNA and Koninklijke NLingenieurs, Explanatory notes to De Nieuwe Regeling 2025 (DNR2025) (in Dutch), version 03, articles 10, 11 and 14, accessed 31 October 2026. bna.nl
- Meijer, F.M. & Visscher, H.J. (2017). Quality control of constructions: European trends and developments. International Journal of Law in the Built Environment, 9(2), 143-161. doi.org