Additional work is rarely a surprise; it's often part of the business model. In the construction sector, where tenders are won on the razor's edge, the contract sum is often just the starting amount. Additional work is the variable that determines the contractor's profit margin—and destroys your budget.
The Financial Minefield
The reality is counter-intuitive: a low quote is often a guarantee of high additional work. Contractors who "bid low" cover themselves by speculating on imperfections in the specifications or inevitable changes. As soon as you, as the client, say "yes" to that one extra wish, the balance of power shifts.
Article 7:755 BW: Your "Nuclear Option"
Most clients pay additional work invoices grudgingly, but without protest. This is unnecessary. The legislator has given you a powerful weapon in Article 7:755 of the Dutch Civil Code.
The contractor is legally obliged to warn you in good time about the price consequences of a change. This is the duty to warn.
The Rule: No warning = no payment. If the contractor fails to report that that "small adjustment" costs €5,000 extra, he is often legally not allowed to charge these costs.
The Exception (The "Should have known" pitfall): The contractor does not have to warn if you as the client "should have understood from yourself" that the change would lead to a price increase. This is what makes lawyers rich.
The "Provisional Sum" Strategy
A provisional sum is often a disguised additional work generator. A contractor puts €15,000 for a kitchen in the budget, knowing that a decent kitchen costs €25,000. The difference of €10,000 is technically additional work, but feels like theft.
The Insider Fix: Demand realistic provisional sums based on market research, not fictitious balancing items to reduce the total price.
Additional Work vs. Reduced Work: The 10% Rule
If you decide not to carry out a part ("reduced work"), don't expect to get the full amount back. Contractors are often allowed to retain a percentage (usually 10%) for lost profit and general costs. This is often in the small print of the general terms and conditions (UAV). Read them.
Protocol: The "Change Order" Discipline
Professionalize your communication to avoid discussions:
No Verbal Order: "Just do it" on the construction site is deadly.
The "Price-Freeze": Do not implement any changes without a fixed price. Do not accept "post-calculation" unless you agree on a ceiling amount.
The Weekly Overview: Have the contractor sign a weekly overview of all additional work. No signature = didn't happen.
Frequently Asked Questions about Additional Work / Variations
When is additional work billable?
Only if the contractor has warned you in time about the price consequences, unless you should have understood it yourself.
What is the risk of provisional sums?
Provisional sums are often underestimated to make the bid look attractive. The difference is billed later as additional work.
Do I get a refund for omissions/reduced work?
Yes, but contractors are often allowed to retain 10% for lost profit and overheads when work is cancelled.
Verify this term directly
Does 'Additional Work / Variations' appear in your contracts? Let our AI check if conditions are favorable.