When collaboration is not included in the contract

The problem only becomes apparent on the construction site: There is a lack of space for the installation of a technical system. The executing company immediately recognizes the problem. However, they were not involved in the planning phase. None of the planners felt responsible for the internal construction logistics. What now costs time and money might have been clarified earlier. BIM, Lean Construction Management, and Integrated Project Delivery, or IPD, address precisely such interfaces. Information should come together earlier, processes better coordinated, and the knowledge of the executing side used already in the planning phase.

For years, these methods have been considered important building blocks for more efficient planning and construction processes. In practice, however, they are spread with varying degrees of prevalence. BIM has become the most established, while Lean and especially IPD are used much less frequently. Legal questions are repeatedly cited as barriers, but these are hurdles that can be managed contractually.

BIM, Lean, and IPD change the rules of the game

Construction projects, of course, do not operate in a legal vacuum. However, the existing rules do not automatically capture every additional task that arises through BIM, Lean, or IPD. Construction and planner contract law has long known the so-called cooperation principle: The parties are supposed to fulfill their own duties while also considering the interests of the other contract party.

In everyday construction, this is evident, for example, in notifications of concerns, hindrances, or additional costs. If a contractor recognizes a disturbance or problem, they should inform the client. This gives the client the opportunity to respond in a timely manner. However, such notifications are quickly perceived as attacks in practice, which is one of the contradictions in an industry that simultaneously demands more cooperation.

BIM, Lean, and IPD also demand more than this classic form of collaboration. They create additional roles, change processes, and shift tasks partly into earlier project phases. At this point, the contract needs to become more specific. The crucial question then is not just: Are the participants working together? But rather: What additional work is actually to be performed? Who takes on this work, and how is it compensated?

BIM: VDI 2552 describes the method, but not tasks and compensation

For BIM, the methodological framework is comparatively well-developed. The VDI Guideline 2552 describes Building Information Modeling as a method for the planning, execution, and operation of constructions based on digital building information models and a collaborative working method. It includes digital data models and consistent data management. DIN ISO 19650 also deals with information management in BIM projects. This describes how BIM should basically function. Nevertheless, for individual projects, it remains to be clarified who assumes which tasks.

An example: The architect creates their model, the specialized planners provide further models for structural framework or technical building equipment. These models must be merged and coordinated with each other, ideally identifying conflicts before they become a problem on site. For these tasks, VDI 2552 includes BIM management and BIM coordination, among others. The BIM management sets the BIM goals and applications and formulates the client information requirements, or AIR. This describes what information and models the client needs from the project participants, when they should be available, and what requirements they should meet. The BIM coordination handles the operational implementation. In practice, BIM management is often the responsibility of the client or specially commissioned specialists. Coordination is often managed by the involved planners, such as the specialized planners for their respective models and the object planning for overall coordination.

HOAI: new regulations, more orientation?

Legally, it becomes interesting when such tasks go beyond the previous planning contract. For planners, the question arises whether a BIM service is already agreed upon or must be additionally commissioned. The new HOAI is supposed to provide guidance for remuneration. However, in its current version of 2021, it does not resolve this question. It describes classic planning services while initially remaining method-neutral: Just deciding to process a project with BIM does not automatically expand the owed scope of performance. In the draft of the new HOAI, which is set to take effect in 2027, BIM services are given more emphasis. This means: If a planner is to take on additional BIM management or further coordination tasks, this must be expressly agreed upon and also remunerated separately.

VOB/C: BIM belongs in the service description

On the execution side, the same question arises. Here, VOB/C plays an important role. Its technical contract terms describe which services are typically included in the individual trades. If a construction company is to take on additional BIM tasks, the service description must clearly state what is expected. Only then can the company calculate the additional effort in its offer.

Thus, the general stipulation "The project will be carried out with BIM" becomes a specific work assignment. The contract must indicate which model a participant is to deliver, what information must be included, and whether their responsibility ends with the delivery of the model or also includes coordination tasks. The clearer this boundary is drawn, the lower the risk of disputes during the project about who was actually supposed to take on which BIM task.

LEAN: never without Client-Lean Requirements (CLR)

In Lean Construction Management, the focus is not the model, but the process. The method originally comes from industrial production and aims to prevent work from stalling due to lack of decisions, incomplete preliminary work, or unavailable materials. For the construction industry, these principles were concretized in VDI 2553, among other things.

For Lean to work in the project, someone needs to organize this process. Often, this is done by a specialized Lean management unit or project management. Other participants also need to allocate time: Planners, site management, and executing companies regularly participate in Lean sessions and coordinate the next steps. This effort thus belongs in the service description and must be considered in the calculation.

Legally, it becomes interesting where Lean encounters tasks already assigned in the project. In phase 8, planners accompany the construction execution and coordinate trades. At the same time, project management often also takes on parts of the fine coordination. If a Lean Construction Manager is added and also controls processes and coordination, responsibilities can overlap. Then, in practice, the question quickly arises: Who should have recognized that a step was not ready? Who had to bring the parties together? And who is responsible if coordination does not occur? Such overlaps can later lead to discussions about liability and responsibility.

Here, too, the contract can clear up uncertainty. Client Lean requirements, or CLR, can define how the Lean process is organized in the project and what involvement is expected from the parties involved. Therefore, the contract should not only state that Lean Construction is being used. It must also distinguish the tasks of Lean Management from construction supervision and project control. One possibility is to clearly assign Lean services to project management. Thus, Lean is not legally a special case. The same principle applies as with BIM: Whoever demands an additional method must also describe the work that arises from it.

IPA: Collaboration becomes a contractual model

Integrated Project Delivery, or IPD, goes deeper into the project organization than BIM or Lean. Designers, construction companies, and possibly important suppliers should collaborate earlier, treat costs more transparently, and resolve conflicts within the project as much as possible. BIM and Lean are often part of this approach. The biggest difference often lies in the contract structure. In Germany, a construction project usually works with individual contracts: The client concludes a separate contract with the architect, the specialist planners, the construction companies, or other parties. Each initially owes the services from their own contract. The client or project organization must maintain collaboration between these contracts.

With a multiparty contract, it's different. Here, the client and the main project partners sign a joint contract. They not only determine their respective services but also set the rules for the joint project: How do they make decisions? How do they handle risks? How are target costs addressed? What happens in the event of conflicts? And how do they delineate liability and responsibility among themselves?

The advantage is apparent: The main parties work within the same contractual framework from the beginning. Costs, risks, and decisions can be considered together rather than being shuffled between several contracts. This aligns with the fundamental idea of IPD.

The disadvantage is also obvious: Such a contract is significantly more unfamiliar and laborious than the classic structure. Liability, risk distribution, subcontracting, and target costs must be rethought and regulated very precisely. Developers who are familiar with classic individual contracts often shy away from this step.

IPA: Where the individual contract suffices

However, those who want to collaborate earlier and more closely do not necessarily have to change the entire contract structure. Many elements of the IPD can also be depicted in individual contracts. A contracting company can already be integrally involved during an early phase of design planning. It then contributes its knowledge on construction process, feasibility, and costs before planning is completed. The planner remains responsible for their planning but receives execution knowledge earlier in the project.

A step contract can be used for this. In the first stage, the construction company is already involved in planning and cost optimization. In Design to Cost, planning is not done first and then calculated, but a given cost limit is considered as a planning parameter from the start. Target Value Design goes a step further: The participants jointly define what benefit the project should offer and what target costs must be adhered to. Planning is then continuously reviewed and adjusted against these goals. Only in the second stage does the actual construction execution follow.

However, the contract must be precise here as well. Should the company merely provide suggestions on feasibility or develop its own solutions? How far does its responsibility extend? Does the planning decision remain with the planner? What is paid for participation in the first stage if it later does not lead to an execution order? The earlier companies are involved in areas traditionally assigned to other project participants, the more important this demarcation becomes.

Conversely, planners can remain longer in the project, for instance, through construction-accompanying quality management or more extensive construction supervision. This does not necessarily change the entire contract model but does alter the specific task distribution.

Integrated collaboration: Handling costs and conflicts

Integrated collaboration also involves how project participants handle costs and conflicts. For more cost transparency, the participants can agree on an Open-Book process. Here, a company discloses its relevant costs, for example, for materials, personnel, or subcontractors. Other project partners can thus understand how prices are composed and how costs develop in the project. This creates transparency before cost issues become a dispute.

The contract can also specify a fixed method for conflicts. One option is ADR procedures – Alternative Dispute Resolution. These are procedures with which the participants aim to resolve disagreements outside of a traditional court proceeding as much as possible. The key is that it is predetermined how a conflict will be treated and who will be involved.

Such rules do not necessarily have to be in a multiparty contract. They can also be included in the individual contracts and formulated there as special contract conditions uniformly. This way, while the participants continue to work based on their respective individual contracts, they follow the same rules on central issues.

Conclusion: BIM, Lean, and IPD – nailed down

Legally, BIM, Lean, and IPD need not be complicated. They do not require a new contract universe for each project. They need contracts that precisely describe what the participants are additionally supposed to do. The client information requirements (CIR) specify what information and models the client needs. Client Lean requirements (CLR) describe how Lean collaboration should be organized. Further rules on planning, costs, and conflict resolution can be bundled as IPD Special Contract Conditions, or IPD-SCC. A step contract can bring execution knowledge earlier into planning. Open-Book rules or agreed-upon conflict resolution procedures can also be integrated into classic contract structures.