1. Why transitional rules must come from the local authority
Three reasons to be careful here, and they apply simultaneously. The transition is still taking shape.
| Reason | Consequence for the reader |
|---|---|
| Transitional provisions are the technical part of the law | public summaries do not cover them |
| Practical application is still forming | the changes are recent |
| Interpretations may differ between authorities at first | until practice converges |
This guide does not set out transitional rules, because the sources do not describe them and guessing would be harmful here. The only reliable answer comes from the authority handling the procedure, and it is worth asking in writing.
2. The largest opportunity for ongoing projects
This is the practical core of the article, and it concerns many projects that are simply waiting. It concerns procedures already under way.
According to institutional sources, the bill reviewed the situations in which it is possible to avoid a detailed plan procedure lasting up to three years and replace it with design conditions, whose procedure usually takes one to two months. The outcome of that review must be checked.
| What design conditions can resolve | Example |
|---|---|
| Erecting a smaller outbuilding on the plot | sauna, garage |
| Specifying the built-up area or the number of storeys | an older detailed plan was narrower |
| Changing the type of structure | a dug well replaced by a bored well |
The difference is an order of magnitude, not a nuance: up to three years versus one to two months. No other change of 2026 comes close in scheduling terms.
3. What it means in scheduling terms
Three consequences for a project waiting on a detailed plan. They concern time and cost.
The first step is a check rather than continued waiting: it is worth establishing whether the intended change now falls under design conditions. If it does, the project schedule may shorten by years, and if it does not, the existing procedure continues unchanged.
The practical recommendation is short: any project waiting on a detailed plan because of a minor change is worth reopening with the local authority. The cost of waiting is invisible here, because nobody assumes the solution may have changed in the meantime.
4. What to check
Four questions for the local authority where a procedure was under way at the moment of entry into force. The answers should be obtained in writing.
| Question | Why it matters |
|---|---|
| Which version of the law applies to my application | it determines everything else |
| Whether documents already submitted remain valid | affects preparation cost |
| Whether the type of procedure changes | permit versus notice, in either direction |
| Whether the change now falls under design conditions | where the project awaits a detailed plan |
The fourth question has the largest financial effect and is asked least often. The reason is human: nobody expects the solution to have changed in the meantime, so the question goes unasked precisely where the answer would be worth most.
5. What applies in any event
Two principles do not depend on the transition, and they limit the extent of the uncertainty. They apply in every procedure.
Permits granted and notices submitted before the changes entered into force do not lapse, and data entered in the building register remain valid. The role of the register did not change, as covered by the register article.
The uncertainty therefore concerns the course of a procedure, not results already achieved. That distinction matters, because it determines what has to be asked and what does not.
Summary and four practical rules
Transitional provisions are the technical part of the law, public summaries do not cover them, and interpretations may differ between authorities at first, so the only reliable answer comes from the authority handling the procedure. The practical core lies elsewhere: in certain cases a detailed plan taking up to three years can be replaced by design conditions whose procedure takes one to two months. This covers erecting a smaller outbuilding, specifying the built-up area or the number of storeys, and changing the type of structure. Permits granted and register entries made before entry into force remain valid.
Four rules: ask the authority handling the procedure for the transitional rules in writing. Do not infer the transition from public summaries. For every project waiting on a detailed plan, check whether design conditions are now sufficient. Document the authority's answer, because practice is still forming and interpretations may change.
This article offers professional orientation as at the date of verification. It does not replace the assessment of the local authority.