HOAI Fee Calculator

Frequently asked questions

Is the fee calculated here legally binding?

No. Everything this calculator outputs is a guideline value and a suggestion. Since HOAI 2021 the minimum and maximum rates are non-binding guideline values (following the 2019 ECJ ruling); the fee is agreed freely between the contracting parties. The calculator is not legal advice.

What are eligible costs under the HOAI?

The construction costs from which the fee is derived. For buildings and interiors, § 33 HOAI counts the costs of the building construction (DIN 276, cost group 300); technical systems (cost group 400) count fully up to 25 percent of the other eligible costs and half beyond that. Land and fees are excluded. The calculator can determine this for you via the DIN 276 input.

How do I find the right fee zone?

Via two official routes: the object lists in the HOAI annexes (typical objects with example assignments, e.g. schools in zone III or IV) and the point rating via evaluation criteria (§ 35 or § 40 HOAI). The zone finder in this calculator covers both routes interactively. The result is a suggestion for orientation.

What do the service phases LP1 to LP9 mean?

The HOAI splits the basic services into nine phases, from basic evaluation (LP1) through design and detailed planning to project aftercare (LP9). Each phase carries a fixed percentage of the total fee; for buildings, e.g. 25 percent for detailed design (LP5) and 32 percent for construction supervision (LP8). The percentages differ per service profile; structural design only has LP1 to LP6.

Are the HOAI rates still binding since 2021?

No. In 2019 the European Court of Justice ruled that the binding minimum and maximum rates violated EU law. Since HOAI 2021 the fee tables are guideline values: they remain the usual basis for negotiation, but the fee can be agreed freely.

How do I calculate the fee above 25 million euros of eligible costs?

The HOAI fee table for buildings ends at 25 million euros. Beyond that, the fee is agreed freely; without an agreement, the customary remuneration per § 632 (2) BGB applies. In practice, the extended RifT tables of the public building administration, which continue the curves up to 500 million euros, serve as a negotiation basis. This calculator shows that orientation on request, clearly separated from the HOAI result.

What is the conversion surcharge and how high is it?

For conversions and modernisations a surcharge on the fee can be agreed: up to 33 percent for buildings and outdoor facilities, up to 50 percent for interiors, structural design and technical equipment. Without an agreement in text form, 20 percent is deemed agreed from average difficulty upwards (§ 6 (2) HOAI).

Are incidental costs included in the fee?

No, incidental costs (travel, reproductions, shipping and more) are added to the fee per § 14 HOAI. They are billed itemised; a flat rate applies only if agreed in text form. There is no statutory default percentage; in the calculator you set the flat rate yourself.

Which service profiles does the calculator cover?

Five: buildings and interiors (§ 34/35), outdoor facilities (§ 39/40), structural design (§ 51/52) and technical equipment (§ 55/56, zones I to III, fee per system group). Each service profile calculates with its own official fee table and its own service-phase percentages.