Calculator — deadlines
Enter the day the works were completed. The calculator names the last day for registering the contractor's lien and puts the warranty and limitation periods beside it — those run from acceptance, and so often from a different day.
The day the works were actually finished — not the day of the final invoice.
Without an entry, the page counts warranty and limitation from the day of completion.
This decides the limitation period under OR Art. 371.
Enter the date of completion
The result appears here. The calculation runs entirely on your device — nothing is transmitted and nothing is stored.
What this rests on
ZGB Art. 837 para. 1 no. 3 gives tradesmen and contractors a claim to a statutory charge on the property. Under Art. 839 para. 2, registration must have taken place no later than four months after the works were completed. Posting the application on the last day is not enough: the registration — or, in a dispute, the provisional registration by the court — must be completed within the deadline.
SIA standard 118 applies only where it has been agreed in the contract. Where it has, the client may raise any defect for two years from acceptance under Art. 172. After that, until the limitation period runs out, only hidden defects can be raised (Art. 180). What applies in the end is decided by your contract, not by this page.
Unless otherwise agreed, the customer's defect claims become time-barred two years after acceptance; for defects in an immovable structure, five years. That is the outer frame within which anything can still be asserted at all.
The lien runs from the completion of the works, warranty and limitation from the acceptance of the works. Those are two dates, and they do not always fall together. Minor remedial work, incidentally, does not push completion back — when it occurred is a question of law if it comes to a dispute.
A guide, not a substitute for judging the individual case
This page works out a date, it does not assess your case. Whether the works are complete, whether SIA 118 was agreed, whether an acceptance took place and who owns the land — everything depends on those, and none of it is in a form. If it gets tight, speak to a lawyer, and well before the last day.
Next
A calculator answers for one property. In the business, the point is that the four months are noticed while they are still running — along with the retention that falls due two years later.
That is exactly what elektro.box does in the business: it keeps the installations with their intervals and their deadlines and speaks up while the matter can still be put right. There is no form for that on this page — your result is above, whether you write to us or not.