Who is responsible for A4-A5 documentation?

A4-A5 documentation is a legal requirement under BR18. The legal responsibility is divided into two levels: a public-law responsibility and a private-law responsibility.

The public-law responsibility always rests with the building owner. It is the building owner that the municipality contacts if documentation is missing or the limit is exceeded. This responsibility cannot be delegated — regardless of what the contracts say. The building owner can outsource the work itself, but the responsibility toward authorities remains with the building owner.

The private-law responsibility — who must deliver data and perform calculations — is distributed via contracts between the parties. This is where AB 18, ABT 18, and ABR 18 come into play.

Responsibility type	Who	Can be delegated?
Public-law (authority)	Building owner	No — never
Private-law (contract)	Depends on contract type	Yes — via contract

The contract type determines how the practical responsibility for A4-A5 data and calculations is distributed. Here are the three most common models:

Design-build (Totalentreprise)

In design-build contracts under ABT 18, the design-build contractor is responsible for design and execution within the agreed scope, as well as obtaining necessary regulatory approvals, cf. §18 and §20. Responsibility for the LCA calculation, including modules A4-A5, and coordination and collection of necessary data from subcontractors depends on the specific contract and the building owner's requirements, but is in practice often placed with the design-build contractor.

General contract (Hovedentreprise)

In general contracts, the main contractor collects data from their own works and subcontractors. But the LCA calculation itself is typically performed by the building owner's advisor. The main contractor is obligated to deliver invoices, fuel receipts, weighing slips, and electricity meter data. Under AB 18 §20, the building owner holds the authority liaison responsibility.

Trade contracts (Fagentreprise)

Trade contracts place the greatest risk on the building owner, who must coordinate data collection from all trade contractors — and ensure no parties fall through the cracks. Without a dedicated coordinator, the risk of missing data is significant.

Contract type	Data collection	LCA calculation	Authority responsibility
Design-build	Design-build contractor	Design-build contractor	Design-build contractor (ABT 18 §18/§20)
General contract	Main contractor	Advisor/owner	Building owner (AB 18 §20)
Trade contracts	Each trade contractor	Advisor/owner	Building owner (AB 18 §20)

Missing or inadequate A4-A5 documentation is not just an administrative issue — it has concrete legal and financial consequences:

• No occupancy permit: The municipality can refuse to issue an occupancy permit if A4-A5 documentation is missing or the limit is exceeded. The building cannot legally be put into use.
• Damage claims from tenants: If the building is leased and the occupancy permit is delayed, tenants can file damage claims against the building owner for lost move-in and rental income.
• Fines: In cases of serious violations, fines may be imposed under the Building Act.
• Breach of contract: If a contractor is contractually obligated to deliver A4-A5 data and fails to do so, this constitutes breach of contract. The building owner can claim damages for resulting losses — e.g. additional advisor work or delayed occupancy permit.

In other words: the question is not whether data must be delivered — but who pays when it isn't.

The best insurance against missing data is clear contractual provisions. Here are the most important measures:

1. Use the "Sustainability Services Supplement 2022"

FRI and Danish Association of Architectural Firms have published a standard supplement that specifically describes sustainability services in advisory agreements. Use it as a starting point for defining who performs the LCA calculation and who delivers data.

2. Specify data delivery in tender documents

State precisely in the tender documents which data the contractor must deliver, in what format, and at what frequency. Examples:

• Monthly reporting of fuel consumption (liters of diesel/petrol per machine)
• Delivery notes with transport distance and material weight for all deliveries
• Quarterly electricity meter readings from the construction site
• Weighing slips for all waste, sorted by fraction

3. Include penalties for non-delivery

Consider daily fines or withholding partial payments if data is not delivered on time. It sounds harsh, but it is far cheaper than standing without an occupancy permit.

4. Define responsibility for subcontractors

The main contractor should contractually obligate their subcontractors to deliver the same data level. Otherwise, the responsibility ends up with the main contractor — and ultimately with the building owner.

Regardless of contract type, some universal recommendations apply:

Party	Recommendation
Building owner	Put A4-A5 on the agenda already in the programming phase. Choose contract type with an eye on the documentation burden. Insist on digital data collection over Excel.
Advisor	Conduct an early LCA screening before construction starts. Define data templates and delivery frequency. Follow up continuously — don't wait until project completion.
Contractor	Establish routines for ongoing registration of fuel, electricity, and waste. Save all delivery notes and invoices systematically. Use a digital tool instead of scattered spreadsheets.

The earlier all parties agree on who delivers what, the less friction at project completion. A45 enables all parties to contribute to the same project documentation — so data doesn't disappear in email chains and file shares. See also our practical guide to data collection.