What an architect costs in Germany and why the HOAI still matters
Anyone who builds, converts or plans an office building in Germany soon asks what the architect will cost. Germany has its own rulebook for this: the Fee Structure for Architects and Engineers (Honorarordnung für Architekten und Ingenieure, HOAI). It describes which services an architect provides, how they are weighted and what fee is appropriate for them. HOAI 2021 has applied since 1 January 2021. It is the basis of our HOAI fee calculator, which lets you recalculate every figure in this article for your own project.
This guide explains the calculation step by step: from eligible costs, fee zone and fee rate to work stages, refurbishment surcharge, expenses and VAT. It ends with a complete worked example.
The HOAI after the ECJ ruling: guidance instead of obligation
Until the end of 2020 the HOAI set binding minimum and maximum rates. As a rule, an architect could neither undercut the minimum nor exceed the maximum. On 4 July 2019 (case C-377/17), the European Court of Justice ruled that this price regulation was incompatible with the EU Services Directive. The legislator responded: under HOAI 2021, the table values are now only guide values (§ 2a HOAI).
This has three practical consequences. First, the fee is freely negotiable and may lie above or below the table values. Second, the agreement must be made in text form; an email is enough. Third, without such an agreement the base rate is deemed agreed (§ 7(1) HOAI). When dealing with consumers, the architect must also point out in text form before the contract is signed that a higher or lower fee than the table values can be agreed. If this notice is missing, the base rate applies instead of a higher fee (§ 7(2)).
Despite this liberalisation, the HOAI remains the key benchmark. Its service descriptions, definitions and fee tables are still used in contracts, tenders and in court when the question is what is reasonable. A reform with higher table values has been announced, but as of 24 September 2026 it had not been adopted. The 2021 version therefore still applies.
Step 1: Eligible costs
The fee is based neither on floor area nor on purchase price, but on the eligible costs (anrechenbare Kosten, § 4 HOAI). These are the net construction costs relevant to the design service. For buildings, the costs of the building structure (cost group 300 under DIN 276) count in full. Under § 33 HOAI, technical systems (cost group 400) count in full up to 25% of the other eligible costs and by half above that, if the architect does not design or supervise them. Land, site development and VAT are excluded.
The cost calculation from the final design is decisive. If it is not yet available, the cost estimate from the preliminary design is used. Our article Eligible costs under the HOAI explains how to determine them in detail. The fee table runs from €25,000 to €25 million. Outside this range there are no guide values.
Step 2: The fee zone
Not every building is equally difficult to design. A carport makes different demands from a concert hall. The HOAI therefore distinguishes five fee zones, from very low (zone I) to very high design requirements (zone V). For buildings, six criteria are decisive: integration into the surroundings, number of functional areas, design and structural requirements, technical systems and fit-out (§ 35(2)).
The object list in Annex 10.2 gives typical cases. Single-family houses fall into zone III or IV, nurseries and primary schools into zone III, universities into zone IV and university hospitals into zone V. How points are scored in borderline cases is covered in Determining the HOAI fee zone.
Step 3: Table value and fee rate
With the eligible costs and the fee zone, you read the table value from § 35(1) HOAI. For each zone the table gives a range: the base rate as the lower value and the upper rate. Example: at €500,000 eligible costs, zone III ranges from €62,900 to €78,449. These amounts apply to 100% of the services, i.e. all nine work stages.
If your costs lie between two table steps, the value is interpolated linearly under § 13 HOAI. At €400,000 the value lies exactly halfway between the €300,000 and €500,000 steps. The base rate in zone III is then €39,981 + 0.5 × (€62,900 − €39,981) = €51,440.50. The upper rate is correspondingly €64,156.50.
Where the fee falls within the range is a matter of negotiation. In practice, the base rate, the middle rate or a percentage in between is often agreed. In the calculator you set this with the "rate within the zone" slider.
Step 4: The work stages
The architect's services are divided into nine work stages (Leistungsphasen). Each stage carries a fixed percentage of the fee (§ 34(3)):
| Stage | Name | Buildings | Interiors |
|---|---|---|---|
| 1 | Basic evaluation | 2% | 2% |
| 2 | Preliminary design | 7% | 7% |
| 3 | Final design | 15% | 15% |
| 4 | Planning permission | 3% | 2% |
| 5 | Construction documents | 25% | 30% |
| 6 | Preparing the tender | 10% | 7% |
| 7 | Assisting with the award | 4% | 3% |
| 8 | Site supervision | 32% | 32% |
| 9 | Post-completion support | 2% | 2% |
If not all stages are commissioned, only the share of the commissioned stages may be charged (§ 8(1)). If you only commission the design up to planning permission (stages 1 to 4), you pay 27% of the table fee for a building. The biggest items are construction documents and site supervision, together 57%. What happens in each stage is described in HOAI work stages 1 to 9.
Step 5: Refurbishment surcharge for existing buildings
Conversions and modernisations take more effort than new builds, because the existing building has to be surveyed, assessed and integrated into the design. The HOAI therefore allows a surcharge on the fee: up to 33% for buildings and up to 50% for interiors (§ 36). If nothing is agreed in text form, a surcharge of 20% applies from average difficulty (§ 6(2)). In addition, existing building fabric that is incorporated can increase the eligible costs. Details are in HOAI refurbishment surcharge.
Step 6: Expenses and VAT
In addition to the fee, the architect may charge the expenses required for the job (§ 14 HOAI). These include postage, copies, travel beyond a 15 km radius and, where applicable, a site office. Without a special agreement, expenses are charged individually. Often a flat rate of around 3 to 6% of the fee is agreed instead. VAT, currently 19%, is added to fee and expenses (§ 16 HOAI) unless the architect uses the small business exemption.
Worked example: single-family house with €400,000 eligible costs
A client plans a single-family house. The cost calculation gives €400,000 eligible costs. The house is assigned to fee zone III, the middle rate is agreed, all nine work stages are commissioned and flat-rate expenses of 5% apply.
1. Table value (interpolated): base rate €51,440.50, upper rate €64,156.50.
2. Middle rate: (€51,440.50 + €64,156.50) ÷ 2 = €57,798.50 for 100% of the services.
3. Work stages 1 to 9 = 100%: fee €57,798.50. Of this, for example, €14,449.63 is for construction documents and €18,495.52 for site supervision.
4. Expenses 5%: €2,889.93. Net total: €60,688.43.
5. VAT 19%: €11,530.80. Total gross fee: €72,219.23.
The fee is thus roughly 14.4% of eligible costs. If it is a conversion with a 20% surcharge, the fee without expenses rises to €69,358.20, and to €86,663.07 gross including expenses.
What the HOAI does not cover
The table values apply only to basic services. Special services such as building surveys, energy consulting, competition entries or a room data book are freely negotiable. Structural engineering and building services design have their own tables and are not included in the architect's fee for buildings. For several identical buildings, § 11(3) provides reductions for repetitions; for repairs, site supervision can be increased by up to 50% under § 12(2).
Tips for the fee agreement
Record the basis of the calculation in writing: eligible costs or the method for determining them, fee zone, fee rate, commissioned work stages, refurbishment surcharge and expenses. Decide whether to commission in stages, for example stages 1 to 4 first and the rest after planning permission. This limits your risk if the project does not go ahead. Compare quotes not only by the total but also by the scope of services.
For financing your project, use the mortgage calculator. For existing buildings, the renovation cost calculator gives a first overview of the construction costs from which eligible costs are derived.
Conclusion
HOAI 2021 no longer prescribes prices, but it provides the recognised calculation scheme for architect fees in Germany. If you know the eligible costs, fee zone, fee rate and work stages, you can quickly put a quote into context. The HOAI fee calculator handles interpolation, surcharges and VAT for you. The results are guide values and do not replace legal advice.