Professional Fees for Architects (HOAI)

Overview

Phase-by-phase billing and documentation of service achievements for architects and engineers per HOAI (Honorarordnung für Architekten und Ingenieure). Validates Grundleistungen completeness before billing, calculates Honorarzonen from building complexity criteria, and produces structured Leistungsnachweis documentation.

Getting Started

Add your source materials to the project workspace, then activate the Professional Fees for Architects (HOAI) skill. The agent will guide you through the process step by step.

Example Chat

You: I need to prepare the billing documentation for LP 3 (Entwurfsplanung) of our residential building project in Munich. Honorarzone III, anrechenbare Kosten are 1.2 million EUR netto.

Agent: I’ll prepare the Leistungsnachweis for LP 3. Let me first set up the documentation template and then we’ll work through each Grundleistung. Do you have the design drawings (M 1:100) and the Kostenberechnung nach DIN 276 ready?

You: Yes, drawings are final and the Kostenberechnung is complete at 1.18 Mio EUR.

Agent: I’ve documented all six Grundleistungen for LP 3 in the Leistungsnachweis. Let me validate completeness before billing. (runs hoai_service_validator)

All Grundleistungen for LP 3 are documented. The Kostenberechnung references DIN 276 and shows a -1.7% deviation from the Kostenschätzung — within acceptable range. LP 3 is ready for billing at 15% of the total Honorar.

Output Excerpt

The skill produces a structured Leistungsnachweis (service documentation) with per-phase checklists:

## LP 3: Entwurfsplanung (15%)

### Grundleistungen

- [x] Erarbeiten der Entwurfsplanung
  → Entwurf v3.2 vom 12.01.2026
- [x] Zeichnerische Darstellung des Gesamtentwurfs (M 1:100)
  → Planliste: E-001 bis E-024
- [x] Verhandlungen über die Genehmigungsfähigkeit
  → Vorgespräch LRA München, 18.11.2025
- [x] Kostenberechnung nach DIN 276
  → 1.180.000 € (netto), Abweichung -1,7%
- [x] Fortschreiben des Terminplans
  → Terminplan v2.1 vom 15.01.2026
- [x] Zusammenfassen und Dokumentieren der Ergebnisse
  → Erläuterungsbericht LP3 vom 20.01.2026

Status LP 3: ABGESCHLOSSEN | Abrechnungsfähig: Ja

Validation Tools

The skill includes two extension tools that automate compliance checks:

• hoai_service_validator — Scans the Leistungsnachweis and verifies that every required Grundleistung for a given Leistungsphase is documented. Reports missing services, DIN 276 cost documentation gaps, and unfilled placeholders. Use before preparing any invoice.

• billing_zone_calculator — Evaluates the six Bewertungsmerkmale (building complexity criteria) and calculates the Honorarzone (I–V). Can also scan existing documents for zone declarations and flag inconsistencies.