For architecture and engineering firms, ZEP includes an integrated HOAI fee calculation (Honorarordnung für Architekten und Ingenieure — German fee schedule for architects and engineers). From fee zone, fee rate, chargeable costs (net), and the chosen service phases, ZEP automatically determines the fee and creates a offer item for each phase.
HOAI template as prerequisite
The HOAI calculation is available as a system-internal template Proposal under HOAI. It appears automatically in the templates dropdown when creating a new proposal — without you having to create it manually. Select it via Proposals > My Proposals > New Proposal > Template „HOAI fee calculation".
In the creation dialog, you first enter the regular master data (customer, title, responsible, etc.) as for any other proposal.
HOAI fee calculation tab
After saving the master data, the additional tab HOAI Fee Calculation appears in the proposal. Here you configure the technical parameters.
Select service profile
In the service profile field, you select the HOAI paragraph used for billing (e.g., „§34 Buildings" for building planning or „§40 Area planning" for landscape architecture). The selection determines the available service phases and the fee table.
Enter chargeable costs (net)
In the chargeable costs (net) field, you enter the calculation basis. Depending on the service profile, label and unit change:
for building planning: Chargeable costs (net) in euros
for area planning: Area in hectares
for other service profiles: Accounting units
ZEP automatically checks minimum and maximum values according to the HOAI fee table and displays an error message if the value is outside the allowed range.
Select fee zone
The fee zone reflects the difficulty level of the project. Depending on the service profile, fee zones I to V are available (e.g., residential buildings usually fee zone III, prestigious structures fee zone IV or V). A higher fee zone leads to a higher fee.
Select fee rate
The fee rate determines where within the fee range of the zone billing takes place. Available are:
Base fee rate — lower value of the fee range
Quarter rate — base fee rate + one quarter of the range
Middle rate — middle value of the fee range (default pre-set)
Three-quarter rate — base fee rate + three quarters of the range
Upper fee rate — upper value of the fee range
Activate service phases
The 9 service phases of HOAI are all activated by default, each with the standard percentage specified in HOAI (e.g., LP 3 Draft Planning: 15%). You can deactivate individual phases if you do not offer them, or adjust the percentages per phase for individual deviations. The sum of active phases does not need to reach 100% — often, only LP 1–5 are offered, for example.
Example residential building in fee zone III
Example: An architecture firm plans a residential building with chargeable costs (net) of 1.2 M €. Inputs:
Service profile: §34 Buildings
Chargeable costs (net): 1,200,000 €
Fee zone: III
Fee rate: Middle
Active phases: LP 1–5 (basic determination to execution planning), LP 6–7 (preparation of award + assistance with award)
Result: ZEP creates 7 fixed price items, one per active service phase, with the respective fee amounts. The total proposal fee is the sum of the active phases.
Fee calculation and item generation
As soon as you save the HOAI parameters, ZEP automatically calculates the total fee based on the HOAI fee tables (interpolated between table values). For each active service phase, an own fixed price item with the unit „Package" is created — with the fee amount calculated for this phase.
In the proposal note, the chosen HOAI parameters are automatically documented (service profile, fee zone, fee rate, chargeable costs (net)) — for internal traceability and possible customer queries.
Note: The generated items can be manually edited after creation, additional items can be inserted, or individual phases renamed. If you subsequently change the HOAI parameters in the HOAI tab, the items are regenerated — manual adjustments are lost in the process.
Add further items
Beyond the HOAI-generated items, you can add supplementary effort or fixed price items for non-HOAI services — for example, construction supervision at an hourly rate, special expert opinions, or ancillary costs. These supplement the HOAI phases at the end of the proposal and are included in the total amount.
After the HOAI calculation
Once the HOAI phases are available as offer items, the normal proposal process continues: add any additional items if needed (e.g., construction supervision at an hourly rate, special expert opinions), create the proposal document, send it to your customer, and transfer it to a project after commissioning. The complete process is described in the article Create and Send Proposals.