Why the fee zone matters so much
Alongside eligible costs, the fee zone is the second big lever in the architect's fee. At €400,000 eligible costs, the base rate is €36,991 in zone I and €72,248 in zone V, almost twice as much. A wrong assignment can therefore quickly cost five figures. Below the result, the HOAI fee calculator shows the ranges of all five zones for your costs.
The five zones at a glance
| Zone | Requirements | Typical cases (Annex 10.2) |
|---|---|---|
| I | very low | carports, canopies, simple temporary buildings |
| II | low | simple garages, simple housing with shared sanitary and kitchen facilities |
| III | average | single-family houses (III–IV), nurseries, primary schools |
| IV | high | universities, hospitals at care levels I and II |
| V | very high | university hospitals, theatres, concert halls and museums (IV–V) |
The object list describes the usual case, not an automatic rule. The wording "as a rule" leaves room for deviation when a project is clearly simpler or more demanding than usual.
The six criteria for buildings
Under § 35(2) HOAI, the zone of a building depends on these criteria:
1. Requirements for integration into the surroundings, for example infill sites, listed buildings or slopes.
2. Number of functional areas, i.e. how many different uses have to be combined.
3. Design requirements.
4. Structural requirements, for example large spans or unusual load-bearing structures.
5. Technical systems.
6. Fit-out, i.e. scope and quality of the interior finishes.
Scoring points in borderline cases
If the criteria do not clearly match one zone, points are awarded (§ 35(4)). Criteria 1 and 4 to 6 receive up to 6 points each, criteria 2 (functional areas) and 3 (design) up to 9 points each. The maximum is 42 points. The zone follows from the total:
| Points | Fee zone |
|---|---|
| up to 10 | I |
| 11 to 18 | II |
| 19 to 26 | III |
| 27 to 34 | IV |
| 35 to 42 | V |
An example: a single-family house on an infill site between neighbouring buildings (integration 4 points), with three functional areas (5 points), upscale design (6 points), standard construction (3 points), a heat pump and mechanical ventilation (4 points) and upscale fit-out (4 points) reaches 26 points. That is just zone III. With a more complex structure it would be zone IV.
Interiors: separate criteria
Different criteria apply to interiors (§ 35(3)): number of functional areas, lighting design, spatial arrangement and proportion, technical systems, colour and material design, and structural detailing. The first four criteria receive up to 6 points each, colour and material design and detailing up to 9 points each. According to Annex 10.3, living rooms with a standard fitted kitchen fall into zone III, while custom-designed kitchens and bathrooms and loft conversions fall into zone IV.
Zones join up seamlessly
A look at the fee table in § 35 shows that the upper rate of one zone is exactly the base rate of the next higher zone. At €400,000 eligible costs, zone III ends at €64,156.50, and that is exactly where zone IV begins. If you see a project on the border between two zones, you can therefore agree zone III at the upper rate. The result is identical to zone IV at the base rate.
Practical tips
Record the chosen zone and the reasoning in the fee agreement. In borderline cases, a documented points assessment helps avoid later disputes. And remember: because the table values have only been guide values since 2021, you can negotiate the rate within a zone instead of arguing about the zone itself. The full calculation is explained in the main article Calculating architect fees in Germany.