The house renovation is underway when a message arrives: the agreed works would be considerably more expensive. Shortly afterwards additional power sockets are discussed, which you had requested yourself. Both give rise to questions of money, but are not automatically the same matter. For a useful clarification it must first become apparent which service belongs to which price basis.
An estimate can be binding to differing degrees
§ 1170a paragraph 1 ABGB governs the cost estimate with an express warranty of its correctness. In that case the contractor cannot demand an increase for the estimated works even if there is an unexpectedly higher effort. Where a contractor’s estimate forming the basis of the contract applies, within the scope of § 5 KSchG its correctness is deemed to be guaranteed, unless the opposite was expressly declared. [ABGB, VERBRAUCHER]
In practice you therefore need the accepted estimate together with the order, annexes and relevant declarations. A subsequent description as a “mere estimate” is not by itself the clarified contractual basis. Conversely, the amount on an initial non-binding discussion note should not be taken without scrutiny as a guaranteed total package.
The service must not change when making the comparison
In the hypothetical case the original order covers the refurbishment of existing rooms. Later the client requests additional electrical connections. In addition the firm reports an unexpected additional effort for a work already estimated.
The client presents both points separately: What was already part of the accepted order? What was requested later? Which additional service was actually agreed? The guaranteed estimate for a certain scope is not an arbitrarily expandable wish list. This article does not decide whether a concrete supplementary claim exists; it makes the difference visible for the examination.
Collect changes with date and exact content. Your own summary can organise conflicting recollections, but does not replace missing proof of an agreement. If it is unclear whether only a possibility was discussed or a change already commissioned, that remains identifiable as the point of dispute.
What becomes important with a non-guaranteed estimate
§ 1170a paragraph 2 contains a specific rule for an unavoidable substantial exceedance: the contractor must notify it without delay; if he fails to do so he loses the additional labour claim specified there. The client may, under the statutory conditions, rescind in respect of work already performed in return for reasonable remuneration. [ABGB]
This does not imply any fixed percentage threshold prescribed by this article. Nor is rescission equivalent to the assertion that all previous work must remain free of charge. Have it explained why the exceedance is said to have been unavoidable, since when it was recognisable and what information you received about it. The legal assessment requires the specific order and sequence of events.
Reply to the message without creating a new price basis too hastily
Request a comprehensible breakdown of the affected items and their causes. Separate existing documents from mere estimates and record which works are planned next. In the event of significant dispute prompt legal support is sensible before making new declarations or initiating drastic measures.
For the preparation of a cost estimate itself § 5 paragraph 1 KSchG also contains a rule on prior notice of a payment obligation. [VERBRAUCHER] This question is to be distinguished from a later exceedance of the contract price for the work.
A well-ordered file explains three things in the end: the original scope of services, the decisive price basis and the actual course of changes. It does not replace a case-by-case decision, but prevents every new invoice from being treated unchecked under the collective term “unexpected additional costs”.