General planner or individual planners?

Design errors rarely arise within one discipline. They arise in between: the opening that the services need and the structure does not know about. The shaft size the architect draws that is too small for the ventilation. The slab thickness in the cost estimate that is not in the structural model. Every one of these gaps costs more on site than at the desk, and every one is a change order that no contract excludes.

The general planner moves these interfaces into its own office. That is its strongest argument. With individual appointments, coordinating and integrating the contributions of the other disciplines is a basic service of the architect in work stages 2, 3 and 5. The architect coordinates, but is not the client of the specialist engineers. If a structural engineer is late or delivers incomplete work, the architect can remind, not instruct. Only the owner can instruct, and for that the owner needs someone who reads the design stages and sees the delay before it reaches the site.

That is the project controller's role, and it is missing in both models. The general planner, too, is a contractor, not a representative. It checks its design against its fee, not against the owner's budget. What an owner's representative does in the design phase is set out in What does an owner's representative do?

With a general planner the position is clear: it owes a defect-free overall design and must accept responsibility for its sub-planners' fault. The owner has one party to claim against. The flip side: only one. If that party's indemnity cover is insufficient for the sum of all disciplines, the owner faces a debtor who cannot pay. The general planner's cover therefore belongs on the table before appointment, project-related and not only as an annual maximum.

With individual planners, each is liable for their own work. Where architect and structural engineer have caused a defect together, they are jointly and severally liable, and the owner can pick the more solvent one. In practice the difficulty lies earlier: the owner must prove whose work was defective. With an interface error, each points at the other. Whoever has documented the design stages and minuted the coordination meetings wins that dispute. Whoever has not often loses it regardless of the merits.

Since the HOAI 2021, the fee tables are reference values, no longer binding minimum and maximum rates; that follows from the 2019 judgment of the Court of Justice of the European Union. The scopes of service for buildings, structural engineering and building services remain the yardstick against which offers can be measured, in both models.

The general planner charges the scopes of its disciplines and, on top, a premium for coordination, assumption of liability and the pricing risk of its sub-planners. The HOAI has no provision for this; the premium is freely negotiated. It is the price of one interface fewer, and it can only be judged with the individual fees placed alongside. That is precisely a task of owner's representation before the design is awarded.

Individual appointments save the premium and cost coordination. Whoever does not have it in-house buys it through project control: under the AHO fee table roughly three to four percent of construction cost at 15 to 20 million euros, more for smaller schemes, for all phases; project preparation and design account for 40 percent of that under the AHO booklet. What determines the fee in detail is set out in What does an owner's representative cost?

The general planner is right for a technically complex building with a high share of building services, for an owner without in-house design leadership who does not want to buy in coordination, and for a tight programme in which alignment rounds between separate offices take too long. The condition is a general planner whose sub-planners you know, and cover that fits the project.

Individual planners are right when the quality of individual disciplines is decisive, for instance a specialised structural engineer for a demanding structure, when the owner has or appoints project control, and when the owner wants to keep the option of replacing one office without re-awarding the entire design. For residential schemes with conventional services this is the more common route.

In both cases the owner needs someone to lead the design: check design stages against budget and programme, prepare decisions, own cost planning and cost control. The general planner relieves the owner of coordinating the designers, not of leading the project.

For our own schemes in project development we decide the question per project and carry the result with our own capital. For clients, before the design is awarded, we place the individual fees alongside the general planner's offer, check scopes, interface schedules and cover, and lead the design in the role of project control in Munich and Bavaria.