Construction disputes and quantum: step by step runs through five practical stages under Swedish procedure: notification of the claim, appointment of a quantum expert, disclosure of cost and schedule records, submission and exchange of quantum reports, and finally determination by the tribunal or court. Each stage has its own deadline and evidentiary requirement, and missing one narrows what can be recovered rather than removing the right to claim.
Who this concerns
The sequence below applies to main contractors and subcontractors pursuing payment for variations, delay or defects, to employers defending a final account, and to their insurers once a claim crystallises into a formal dispute. It also applies to foreign parent companies of Swedish project subsidiaries and to foreign contractors working on Swedish sites under a Swedish-law contract.
Most Swedish construction contracts of any size incorporate one of the AB 04 or ABT 06 standard forms, industry-drafted general conditions covering variations, delay damages and the final account procedure. Where a contract uses these forms, the quantum process below runs inside their notice and final-account timetable rather than against a bare statutory backdrop. Where it does not, the general rules on damages and evidence apply without that additional layer of contractual deadlines.
The trigger is usually one of three events: a variation order disputed on price, a completion date missed with liquidated damages claimed, or a final account rejected in whole or in part. From that point, the clock on notice periods and limitation starts running, and the choice of forum, arbitration or the ordinary courts, is usually already fixed by the contract.
What the law says
Swedish law does not prescribe a single quantum methodology for construction claims. Recoverable loss is assessed under the general rules on damages, read together with whatever the contract itself says about variations, delay damages and the final account. Where the parties have agreed arbitration, the Swedish Arbitration Act governs the procedure but leaves the method of quantifying loss to the tribunal; where the dispute goes to the ordinary courts, the general rules of civil procedure apply instead.
Under Swedish law as it currently stands, both courts and arbitral tribunals routinely accept expert quantum evidence but are not bound to adopt it wholesale. A tribunal can, and often does, accept the expert's method while adjusting individual cost heads it considers unsupported by the underlying records. This is the single most common source of surprise for parties who treat a quantum report as a fixed number rather than as a starting position for cross-examination and adjustment.
How it works in practice
Step 1: Notify the claim within the contractual window
If the contract incorporates AB 04 or ABT 06, the notice period for a variation or delay claim is set by the contract itself, not by statute, and it is short. A notice sent late, or sent to the wrong counterpart within a group structure, can extinguish part of the claim before quantum is even discussed. Preserve the original notice, the delivery record and any acknowledgement received.
Step 2: Appoint an independent quantum expert
The expert's independence matters more in Sweden than the size of their firm. A tribunal weighs a report less if the expert has an ongoing commercial relationship with the instructing party, and it will say so in the award. Instruct the expert before, not after, the position on liability has hardened, so that the quantum method can be built on a full document set rather than retrofitted to a conclusion already reached.
Step 3: Disclose cost, schedule and variation records
Disclosure in Swedish arbitration and litigation is narrower than in common-law jurisdictions: there is no general duty to search for adverse documents, and requests must identify categories of record with reasonable precision. Cost ledgers, site diaries, variation instructions and correspondence on programme slippage are the categories that decide most quantum disputes. Where a party resists disclosure of cost data on confidentiality grounds, the resistance itself is often read as evidence that the figures do not support the claim. For the mechanics of what a tribunal or court can compel and what happens when a party simply refuses, see evidence disclosure and witness practice in Swedish disputes.
Where the contractor's cost build-up includes pricing methods or supplier terms it treats as commercially sensitive, disclosure can be limited to the tribunal and opposing counsel under a confidentiality regime rather than refused outright; refusal on that basis alone rarely succeeds.
Step 4: Build the quantum report on one consistent method
Swedish tribunals expect a single, stated method applied consistently across every head of claim: either a global cost comparison against the contract sum, or a head-by-head build-up tied to specific variations and delay events. Mixing methods within one report, using a global approach for delay and a head-by-head approach for variations, is the fastest way to have an otherwise sound report discounted.
Step 5: Exchange counter-quantum and narrow the disputed heads
The responding party produces its own quantum position, usually lower, and the two reports are compared head by head. This exchange is where most of the eventual award is actually decided: heads on which both experts agree the method, even if not the figure, tend to survive; heads where the methods diverge entirely tend to be resolved against whichever side cannot explain its choice of method under questioning.
Step 6: Use the pre-hearing window to settle what can be settled
Once counter-quantum is exchanged, the range of realistic outcomes on each head is usually visible to both sides. This is the point at which settlement on the narrower, more defensible heads is most efficient, leaving only the genuinely contested items for determination. Waiting until after the hearing to make this assessment usually means paying for a hearing on points that were always going to settle.
Step 7: Obtain determination, award or judgment
An arbitral award on quantum is final and not open to appeal on the merits; a court judgment can be appealed within the ordinary time limits. Where the counterparty, its assets, or the group treasury sit outside Sweden, the practical value of either outcome depends on whether it can be enforced abroad, which is a separate question from whether it was correctly decided.
What to check before instructing an expert
- The governing contract form and whether it incorporates AB 04, ABT 06, or bespoke terms with their own notice and final-account deadlines
- Whether notice of each disputed head was given within the contractual window, and whether proof of delivery exists
- Whether the cost records support a head-by-head build-up or only a global comparison
- Whether the counterparty, its parent, or its principal assets sit inside or outside Sweden
- Whether the contract specifies arbitration or the ordinary courts, and whether that choice was actually followed in prior correspondence
- Whether any part of the claim touches a supplier or subcontractor currently in, or approaching, a reconstruction procedure
FAQ
#### What mistakes cost the most when protecting trade secrets during employee mobility?
The costliest mistake is disclosing pricing methods, supplier terms or cost build-ups to a departing employee or a competing contractor without a written confidentiality restriction in place beforehand; once disclosed, recovery depends on proving the information was in fact secret and that reasonable steps were taken to keep it so. See trade secret protection and employee mobility for how that assessment is made.
#### In an asset deal, who decides what happens to an ongoing construction claim?
Where a contractor's business, rather than its shares, is sold mid-dispute, the claim and the corresponding liability transfer with the undertaking only if the sale documentation says so expressly; silence usually leaves the claim with the selling entity even after the operational business has moved. The mechanics of that transfer are set out in asset deals and transfer of undertakings.
#### What is företagsrekonstruktion and why does it matter in a construction dispute?
Företagsrekonstruktion is the Swedish court-supervised reorganisation procedure available to a business in financial difficulty short of bankruptcy. If a subcontractor or main contractor enters this procedure while a quantum dispute is live, ordinary enforcement against that party is suspended and the claim is instead handled inside the reconstruction process. See the företagsrekonstruktion glossary entry for how that affects an existing claim.
The numbers
Swedish law does not fix a statutory number of days for serving a quantum report, nor a fixed percentage threshold for what counts as a material variation; both are set by the contract, where one exists, or left to the tribunal's or court's case management. Any deadline quoted in general terms without reference to the specific contract or procedural order in front of you should be treated as indicative only. What is fixed by the contract, where AB 04 or ABT 06 applies, is the notice period for individual claims and the timetable for the final account; those figures come from the contract itself and vary by project.
Where it usually goes wrong
The most common failure is treating the contractual notice period as a formality. Under AB 04 and ABT 06, a variation or delay claim not notified within the stated window is at real risk of being time-barred in whole, regardless of how strong the underlying quantum evidence is. No amount of expert work repairs a notice given too late.
The second failure is instructing the quantum expert only after the liability argument has been fully drafted, so the report is built to fit a conclusion rather than to test it. Tribunals notice this in cross-examination, and it costs credibility on every head of claim, not only the weak ones.
The third failure is assuming the counterparty will still be solvent, and still be the counterparty, by the time an award or judgment is obtained. If the paying party's business is sold as an asset deal, or enters företagsrekonstruktion, the practical value of the claim changes even though the legal merits have not. Where the counterparty, or its principal assets, sit outside Sweden from the outset, obtaining a domestic award or judgment is only the first half of the problem; enforcing it abroad is the second, and it is a distinct exercise with its own requirements.
What to do next
The steps above cover what a party can and should organise itself: notice, disclosure, a consistent quantum method, and a realistic settlement window before the hearing. Where they stop being useful is the point where the counterparty, or the assets that would satisfy an award, sit in another jurisdiction, because at that point the question is no longer how the claim is quantified but whether the result can be turned into payment. That question is addressed in recognition and enforcement of a foreign award.
For the broader set of procedures in this practice, start from the disputes and arbitration hub. Where the position on liability or quantum is not yet clear enough to plan around, a preliminary assessment is the next step; book one here.