Cost estimate vs quote – what is the difference?

A cost estimate is a non-binding forecast of costs, whereas a quote is a legally binding declaration with fixed prices. The key difference: with a cost estimate, the contractor may adjust costs later; with a quote, they may not. Anyone building or renovating should understand this distinction before placing an order.

Key points at a glance

• Cost estimate = non-binding: deviations of up to 15–20 % are permissible (§ 650 BGB) — without written terms, there is no budget certainty
• Quote = legally binding under § 145 BGB: contractors cannot increase prices later while the scope remains the same
• Always request a binding quote before awarding the contract — BSB expressly recommends this for all construction projects
• KfW and BAFA generally only accept binding quotes for funding applications, not cost estimates

What is a cost estimate?

A cost estimate (frequently abbreviated KVA in German) forecasts the likely costs of a construction project. Prepared by the tradesperson or construction company, it gives the client an indication of approximately what costs to expect. According to the Chamber of Crafts (HWK), the cost estimate is the most frequently used costing document for smaller trade contracts.⁴

The legal basis is found in § 632(3) BGB: this states that, unless otherwise agreed, no payment is due for a cost estimate. This means the contractor generally cannot charge for preparing one unless expressly agreed beforehand.

Non-binding nature and tolerance limits

A cost estimate is generally non-binding. The actual invoice amount may differ from the estimated figure. Case law has established a tolerance for this: deviations of 15 to 20 % are generally considered acceptable.¹ If the difference exceeds this, the contractor must inform the client immediately (§ 650 BGB).

In practice: for a bathroom refurbishment estimated at 30,000 euros, a final invoice of up to 36,000 euros (20 % extra) would still be within range. From 37,000 euros, problems arise if the contractor did not give timely notice of the overrun.

When does a cost estimate become binding?

A cost estimate can become binding if this is expressly agreed. The wording in the document is decisive. If it says "binding cost estimate" or "fixed-price guarantee", the contractor is bound by the stated prices. In this case, the estimate approaches a quote.

Even if the estimate is very detailed and the contractor verbally assures you that the prices are "fixed", this may legally be regarded as binding. In a dispute, the overall circumstances matter.

What is a construction quote?

A quote (also called an offer) is a legally binding declaration under § 145 BGB.⁵ The contractor thereby declares that they will carry out the specified work at the stated prices. When the client accepts the quote, a contract is formed.

Binding effect and quote validity periods

The contractor is bound by the quote during its validity period. A typical construction quote is valid for 4 to 6 weeks. Within this period, the client can accept without the contractor being allowed to change the prices.

Once the period expires, the binding effect ends. The contractor can then submit a new quote with revised terms. It is therefore worth watching validity periods if you want to compare several quotes.

Price guarantee in a quote

The biggest advantage of a quote: you know exactly what the work will cost. The contractor cannot make additional claims while the scope remains unchanged. Extra work not included in the quote must be commissioned separately. The Bauherren-Schutzbund (BSB) recommends always requesting a binding quote rather than a cost estimate before awarding a contract, because only this ensures budget certainty.⁶

Find more on what to look for when reviewing quotes in our Guide: reviewing a construction quote.

The main differences at a glance

The following table summarises the specific differences between a cost estimate and a quote:

When is a cost estimate useful?

A cost estimate is particularly useful during early planning, when you have not yet made specific decisions. Typical situations:

• Budget planning: You want to know whether your project is financially realistic before starting detailed planning. A cost estimate gives a rough guide without committing you yet.
• Shortlisting providers: If you approach three or four contractors to get a feel for pricing, a cost estimate is sufficient. Estimates are comparable even though they are not binding.
• Complex projects with uncertainties: For period property refurbishment or alterations where the exact work only becomes apparent during construction, a binding quote is often difficult to calculate. The contractor then uses a cost estimate to retain flexibility.

An overview of current renovation prices is available in our Guide to renovation costs 2026.

When should you request a quote?

Once you have chosen a contractor and the work can be described sufficiently specifically, you should request a binding quote. This applies particularly in these cases:

• Before awarding the contract: Do not sign a contract based on a cost estimate if you need budget certainty. Insist on a quote with fixed prices.
• With a fixed budget: If your financial limits are tight, a quote protects against unexpected cost increases. The contractor cannot make additional claims while the scope remains the same.
• When comparing several contractors: Binding quotes make comparisons fair. With cost estimates, you do not know how close the final price will be to the estimate.
• For financing or funding: Banks and funding bodies (KfW, BAFA) generally require binding quotes as a basis for approval.⁷ A cost estimate is usually insufficient for them.

Typical pitfalls

In practice, the boundaries between a cost estimate and a quote often blur. This causes misunderstandings and, at worst, unexpected additional costs. The most common problems:

1. The estimate is labelled a "quote"

Many contractors use the terms interchangeably. A document headed "Quote" may legally still be a cost estimate if it contains wording such as "estimated costs", "approximate prices" or "prices subject to change". The content, rather than the heading, is decisive.²

Watch the wording. If prices are marked "anticipated" or "non-binding", it is a cost estimate regardless of what the document's heading says.

2. The tolerance limit is exceeded

An invoice may differ from a cost estimate, but not without limit. If the difference exceeds the 15-to-20-per-cent threshold, the client has rights. Many project owners do not know this and pay inflated invoices without questioning them.

3. Missing breakdown

An estimate stating only a lump sum is of little use. Without a breakdown of items, quantities and unit rates, you cannot understand how the price is calculated. Nor can you check which work is included and which is not.

We explain how to identify such weaknesses systematically in the article Warning signs of overpriced construction quotes.

4. Verbal promises without written confirmation

"The price will stay the same" is a common verbal statement. Without written confirmation, it is difficult to enforce in a dispute. The Verband Privater Bauherren (VPB) points out that verbal price promises generally cannot be proved in court if a dispute arises.⁸ Always insist on written clarification of whether a price is binding or non-binding.

What to do if costs overrun?

If actual costs substantially exceed the estimate, you as client have clear rights. The most important provision is found in § 650 BGB.

The contractor's duty to notify

As soon as it becomes foreseeable that costs will substantially exceed the estimate, the contractor must inform you immediately (§ 650(2) BGB). In practice, "substantially" means more than 15 to 20 % above the original estimate.³

If the contractor fails to give notice, they may be liable for damages. In this case, you have strong grounds for not bearing the additional costs in full.

Right to terminate for cost overruns

Under § 650(1) BGB, you have an extraordinary right to terminate if the cost estimate is substantially exceeded. This means you can terminate the contract and only have to pay for work completed up to that point, rather than the entire contract value.

In practice, terminating midway through construction is naturally difficult. Negotiating the additional costs is often more sensible. But knowing this right alone strengthens your negotiating position.

Practical steps if costs overrun

1. Compare invoice with estimate: Compare actual costs with the original estimate. Which items differ, and by how much?
2. Check the duty to notify: Did the contractor inform you of the additional costs in time? If not, this is a strong argument in your favour.
3. Respond in writing: Tell the contractor in writing that you do not accept the additional costs, and explain your position.
4. Obtain a professional assessment: For larger amounts, a professional review of the estimate and invoice is worthwhile.

Read how to avoid additional claims and variation costs more generally in the Guide to additional charges.

Provider comparison: professional review

Whether a cost estimate or a quote, both documents should be reviewed before awarding the contract. A professional review identifies weaknesses that non-specialists often miss. The following table shows the usual providers and their terms:

Cleverbauen24 also offers a free Quickcheck providing an initial assessment within minutes. This lets you quickly see whether a more detailed review makes sense.

Frequently asked questions

Is a cost estimate binding?

Generally, no. A cost estimate is a forecast, not a price guarantee. The contractor may deviate from it within reasonable limits (generally 15 to 20 %). An estimate only becomes binding if this is expressly agreed, for example through the wording "binding cost estimate".

Can a contractor charge for a cost estimate?

Yes, but only if agreed beforehand. Under § 632(3) BGB, no payment is due for a cost estimate unless otherwise established. In practice, most contractors do not charge for it. Some businesses charge a fee for elaborate estimates but offset it against the contract value if commissioned.

What happens if the contractor does not give notice of costs?

If the contractor does not report a cost overrun in time, they breach their duty to notify under § 650(2) BGB. You may then claim damages. Specifically, you do not have to pay additional costs beyond the tolerance limit if you would have terminated the contract had you been informed in time.

Should I always request a quote instead of an estimate?

Not necessarily. During early planning, when the precise scope is not yet established, a cost estimate is more useful. Once you have chosen a contractor and the work can be clearly described, insist on a binding quote. Before signing at the latest, a fixed-price quote is the safer route.

Can I have a cost estimate converted into a quote?

Yes. You can ask the contractor to convert the estimate into a binding quote. The scope must be sufficiently defined for this. The contractor then calculates binding prices that cannot subsequently be changed. Chambers of Crafts confirm that this conversion is common practice and reputable businesses carry it out without difficulty.⁹

Sources

1. § 650 BGB – cost estimate (German Civil Code)
2. Consumer advice centre – cost estimates: what to look for
3. § 632(3) BGB – payment for cost estimates (German Civil Code)
4. Munich Chamber of Crafts – cost estimates in the trades: binding nature and tolerance limits
5. § 145 BGB – binding effect of an offer (German Civil Code)
6. BSB, Bauherren-Schutzbund e.V. – construction contract guide: binding quote before awarding the contract
7. KfW – BEG: application documents and requirements (binding quote required)
8. VPB, Verband Privater Bauherren – construction contracts: verbal promises and written form
9. Munich Chamber of Crafts – converting a cost estimate into a binding quote