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Key Takeaways from this article
- The HOAI structures construction projects in Germany into nine clearly defined service phases, from the initial project idea to final documentation.
- Each phase has a specific purpose and helps create clarity around responsibilities, deliverables, and planning steps throughout the project.
- For clients, architects, and project planners, the HOAI provides a reliable framework for transparent fee allocation and more structured project execution.
- Understanding all nine phases helps teams manage construction projects more efficiently and reduce confusion across planning, approval, tendering, and execution.
The HOAI, acronym for "Honorarordnung für Architekten und Ingenieure" (Honorarium regulations for architects and engineers) is a federal ordinance regulating the fees for architectural and engineering services in Germany. It defines the phases of service for construction projects in Germany. These nine phases structure the entire planning and construction process, from the initial idea to completion. Architects, construction managers, and project planners benefit from a clear structure that defines fees and responsibilities.
This article provides an overview of all nine phases of service and explains why they are important for clients, architects, and project planners. Detailed information on each phase can be found in our follow-up articles.
Overview of the Phases According to HOAI
The HOAI divides construction projects into nine consecutive phases:
- Basic Evaluation Phase
- Preliminary Planning (Project and Planning Preparation)
- Design Planning (System and Integration Planning)
- Approval Planning
- Execution Planning
- Preparation of Contract Award
- Participation in Contract Award
- Project Supervision (Construction Supervision)
- Project Support and Documentation
Each of these phases serves a specific function in the planning process and is compensated accordingly.

Phase 1: Preliminary Investigation
In this phase, the basic framework conditions of the project are analyzed. This includes clarifying the client's wishes, regulatory requirements, and initial site analysis. It forms the basis for the subsequent planning steps.
Phase 2: Basic Planning
Here, initial concepts and feasibility studies are developed. Construction costs are roughly estimated, and alternative solutions are discussed. The goal is to create a well-informed decision-making basis for the client.
Phase 3: Design Planning
This phase involves the detailed planning of the construction project. Floor plans, sections, and elevations are created to develop a viable design solution. Cost calculations are also further refined here.
Phase 4: Approval Planning
In this phase, building applications are submitted to the relevant authorities. All necessary documents for obtaining approval are prepared and coordinated. This phase is crucial for obtaining legal permits.
Phase 5: Execution Planning
In this phase, the planning is developed in detail. Construction drawings include precise measurements and material specifications, serving as the basis for construction execution.
Phase 6: Preparation of Awarding
The individual trades are defined in tenders. Bills of quantities and contract documents are prepared to ensure a transparent awarding process.
Phase 7: Participation in Awarding
Here, offers are reviewed, bidders are compared, and awarding recommendations are made. The goal is to make a cost- and quality-optimized selection of contractors.
Phase 8: Project Supervision
This phase includes construction supervision, checking the execution, and coordinating the trades. Inspections and defect checks ensure the quality of the construction work.
Phase 9: Project Maintenance and Documentation
After completion, documentation and defect tracking follow. Warranty periods are monitored, and final documents for the client are prepared.
Conclusion
The HOAI phases of service provide a structured approach to construction projects. They enable transparent fee determination and a clear delineation of responsibilities. Detailed articles on the individual phases can be found in our follow-up posts.This comprehensive consideration of all nine phases highlights how crucial each phase is to the success of a construction project. Architects and project planners can efficiently manage their tasks and ensure that all requirements are met.










