A purely domestic instrument
The territorial scope is narrower than most treatments suggest. The ordinance applies to service providers established in Germany whose services are additionally provided from within Germany.
| Situation | Does the HOAI apply by force of the ordinance |
|---|---|
| Established in Germany, providing from Germany | yes |
| Established abroad, project in Germany | no |
| Established in Germany, providing from abroad | no, not automatically |
Both conditions must therefore be met together. A design practice established abroad does not fall under the HOAI, even where it designs a project in Germany.
The reason is European: the territorial restriction was necessary to comply with the Services Directive. That same directive later brought about the end of binding price law.
For cross-border projects this means that applying the HOAI is a matter of agreement. It can be adopted contractually but does not apply by force of the ordinance.
How the ordinance is structured
The HOAI arranges the service profiles into three specialist parts and one annex. The governing reference quantity changes between the parts, which is the commonest source of error in cross-disciplinary work.
| Part | Content | Governing reference quantity |
|---|---|---|
| Part 2 | Spatial planning | area size |
| Part 3 | Object design | chargeable costs |
| Part 4 | Specialist design | chargeable costs |
| Annex 1 | Further specialist and advisory services | depends on the profile |
The second column contains a difference that matters in cross-disciplinary work. Spatial planning is calculated by area, object and specialist design by chargeable costs. Moving between the two means the system cannot be transferred.
For parts 3 and 4 a further rule applies: what governs are the chargeable costs based on the cost calculation, and only where none exists, those of the cost estimate. The order is mandatory and not a matter of choice.
The individual profiles are covered in the article on the other service profiles. That article also sets out which reference quantity applies to which profile.
Basic services and additional services
The ordinance defines basic services as those regularly performed within spatial, object or specialist design, generally necessary for the proper performance of a commission and captured in service profiles. All three features must be present together.
Alongside them, additional services may be agreed. Their listing is expressly not exhaustive, and they may also be agreed for service profiles and work phases to which they are not allocated, so long as they do not constitute basic services there.
The boundary is covered in the article on additional services. That article also sets out what applies in the absence of a valid agreement.
What Annex 1 covers
Annex 1 contains further specialist and advisory services, including environmental impact studies, building physics, geotechnics and engineering surveying. Its status shifted with the 2021 reform.
Its status shifted with the reform. Under the former price law the fees of parts 2 to 4 were bindingly regulated and those of Annex 1 were not. Since 2021 no fee level is binding, and the services of Annex 1 have been largely placed on the same footing as the other basic services.
In practice this means in particular that the fallback of the base fee rate, where no agreement in text form exists, applies to these services too. The formal requirement therefore applies without distinction.
Where the limits lie
The HOAI is price law, not a law of obligations. It describes services in order to make fees calculable, not in order to create duties.
A series of questions therefore goes unanswered by it, and all of them concern the core of the contractual relationship. They must accordingly be settled in the contract without exception.
| Open question | Where it is governed |
|---|---|
| What is contractually owed | contract, law of works contracts |
| Who is liable for defects | law of works contracts, contract |
| When may the contract be terminated | law of works contracts, contract |
| Who holds the copyright | copyright law |
| What insurance is required | state professional law, contract |
All these follow from the contract and from general contract law. The article on what the HOAI does not govern covers them in detail.
Looking ahead
A reform process has been running for several years. Two expert reports are available, one on the service profiles and one on fee levels, and they propose substantial changes.
The process has been delayed repeatedly and was at times halted. The current position is covered in the article on the HOAI reform.
Related articles
This article reflects the position of the rules and case law at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.