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The other service profiles at a glance

📐 Article7 min read

What you will learn Which service profiles the HOAI recognises, why the percentages differ considerably between them, what special rule applies to structural design, and why spatial planning uses a different reference quantity.

The service profile for buildings and interiors is the best known but only one of several. The others follow the same system with different figures, and those figures cannot be transferred.

The structure

Part Service profiles
Part 2 Spatial planning land use plan, development plan, landscape plan, green space plan, landscape framework plan, landscape accompanying plan, management and development plan
Part 3 Object design buildings and interiors, open spaces, engineering structures, transport works
Part 4 Specialist design structural design, building services
Annex 1 environmental impact study, building physics, geotechnics, engineering surveying

Each profile has its own annex containing the catalogue of its basic services and examples of additional services. The catalogues do not coincide with one another.

The reference quantities differ

The most fundamental difference concerns not the percentages but the quantity the fee hangs on. It runs between part 2 on one side and parts 3 and 4 on the other.

Part Reference quantity Basis
Part 2, area planning the size of the area in hectares, together with the fee zone the planning scope itself
Parts 3 and 4, object and specialist design the chargeable costs of the object the cost calculation, failing that the cost estimate

Moving from spatial planning to object design therefore means the system cannot be transferred. Fee zones are also determined by their own assessment criteria within each profile.

The percentages diverge considerably

A comparison shows how far the weighting differs between two profiles within object design. Both belong to the same part of the ordinance.

Work phase Buildings Transport works
1 Initial appraisal 2 % 2 %
2 Concept design 7 % 20 %
3 Developed design 15 % 25 %
4 Consent design 3 % 8 %
5 Detailed design 25 % 15 %
6 Preparing procurement 10 % 10 %
7 Assisting procurement 4 % 4 %
8 Construction supervision 32 % 15 %
9 Aftercare 2 % 1 %

The difference is structural rather than incidental. For buildings the weight sits in construction supervision at 32 per cent; for transport works it sits in design, with 45 per cent for concept and developed design alone.

That makes substantive sense, because the centre of gravity of the work differs. A transport scheme requires extensive alignment and consultation work during design, while construction is less supervision-intensive than a building.

Practical consequence: anyone working across profiles must calculate per profile and may transfer no values. A partial commission to work phase 4 means 27 per cent for buildings and 55 per cent for transport works, that is more than double.

The special rule for structural design

Structural design is the engineering design for object design of buildings and engineering structures. A separate rule applies to its chargeable costs, departing from the object design system.

For buildings and associated structures, fixed shares apply in place of the threshold rule. They do not depend on the level of the costs and are therefore simpler to handle.

Cost share Chargeable for structural design
Fabric costs 55 %
Cost of technical installations 10 %

The rule is immediately intelligible: the structural engineer deals with part of the fabric and only marginally with the technical installations. It also shows that chargeable costs are not a property of the building but a property of the particular design service.

For object design of buildings, by contrast, the threshold rule for technical installations applies, covered in the branch on chargeable costs. Applying both rules together would be wrong.

Building services design

The building services profile is the specialist design for the installations of cost group 400. It likewise follows nine work phases with its own percentages.

One point matters for collaboration with the lead designer: the cost group 400 figures in the lead designer's cost calculation come from this specialist design. Where it is commissioned only after work phase 4, the lead designer must work from benchmarks.

Since the level of cost group 400 also governs the threshold rule, an understated allowance acts twice over. The system is covered in the article on KG 400.

Annex 1

Annex 1 contains further specialist and advisory services: environmental impact studies, building physics, geotechnics and engineering surveying. They sit outside parts 2 to 4.

Its status shifted with the reform. Under the former price law the fees of parts 2 to 4 were bindingly regulated and those of Annex 1 expressly were not. Since 2021 no fee level is binding, and the services of Annex 1 are largely on the same footing as the other basic services.

In practice this means in particular that the fallback of the base fee rate, where no agreement in text form exists, applies to these services too. Performing them without agreeing the level in text form lands you at that rate.

What to watch across several profiles

Where a commission covers services from several profiles, calculation proceeds separately per profile. Two points need settling.

To be settled Why
Delimiting chargeable costs each profile has its own rules on which costs are chargeable; a common fee basis for all services is the exception
Handling de minimis thresholds for open spaces, separate fee calculation is omitted where it would fall below a certain level of chargeable costs

Both belong named in the contract, because the allocation is hard to reconstruct afterwards. The dispute then arises in the final account rather than in the negotiation.

This article reflects the position of the rules and case law at the date of checking and serves professional orientation. It does not constitute legal advice and does not replace assessment of the individual case.

Frequently asked questions

Besides buildings, there are open spaces, engineering structures, structural design and services engineering. The article sets them out.

No, they differ by service profile. Comparing percentages without the reference misleads.

Considerably, because the effort and structure of the services differ. The article shows the differences.

A special rule applies to it, which the article describes. It concerns the chargeable costs.

HOAI work phases: fees and service profiles for architects