Introduction
The foundation package is a key cost and risk driver in offshore wind projects, with early design decisions directly influencing the feasibility, safety, and efficiency of the construction campaign. Parameters such as foundation type, geometry, weight, and manufacturing philosophy are typically defined during early development stages, yet their implications for vessels, ports, metocean conditions, and offshore execution are often not fully assessed at that point. As offshore wind projects continue to grow in scale and complexity—driven by larger turbines, heavier foundations, deeper waters and increasingly constrained installation resources—ensuring that foundation concepts are developed with installation in mind becomes increasingly important. However, in many projects, Transport and Installation (T&I) expertise is still engaged only after the foundation concept has been established, an approach that frequently leads to design rework, schedule pressure, and budget overruns in later project phases. Integrating T&I expertise early in the development of the foundation package allows installation constraints and opportunities to be considered alongside engineering requirements, supporting more robust, cost-effective, and lower-risk project concepts.
The common problem: Late T&I Engagement
In offshore wind projects, T&I expertise is often introduced after the foundation concept has been selected and developed. This approach is usually justified by the perceived contribution of the foundation package to overall project CAPEX. Historically, foundation procurement and installation have represented a relatively limited share of total offshore wind costs, with foundations typically accounting for around 12% of CAPEX for procurement and approximately 5% for T&I activities in a typical project.
Another factor contributing to late T&I engagement is the limited availability of reliable geotechnical data in the early stages. High-quality geotechnical information requires dedicated site investigation campaigns, which are typically scheduled once projects progress beyond the initial concept phases. Without detailed soil data, foundation selection and preliminary design are often based on simplified or conservative assumptions, making it harder to assess installation feasibility and associated risks at an early stage.
At the same time, the increasing scale of wind turbines and the growing complexity of offshore installation are steadily raising the risk profile of the foundation package. Larger and heavier foundations, stricter environmental and noise mitigation requirements, installation in harder and more variable soil conditions, and tighter offshore execution windows all contribute to greater technical and operational complexity. In addition, the size and weight of foundation components increasingly place demands on port infrastructure, including quay load capacity, available laydown areas, lifting capability, and hinterland logistics. When these constraints are identified late, projects may face the need for port upgrades or new infrastructure, potentially triggering lengthy development timelines and early financial commitments well ahead of FID.
Such late involvement often results in foundation concepts that, while structurally compliant, create practical challenges during construction, such as:
- Difficult or impractical transportation arrangements
- Challenging handling and storage at marshalling ports
- Complex or marginal lifting and offshore installation operations
- Dependence on unrealistic vessel availability or scarce, highly specialised installation equipment
- Requirement for unplanned port upgrades or infrastructure development to accommodate large components
As these risks materialize, T&I CAPEX can rise sharply, potentially exceeding the contingencies considered in the early budget for the business case typically used during bid development. In some recent projects, it has been observed that T&I costs have increased from the initial 5% CAPEX assumption to match procurement costs, meaning that installing the foundations can become as expensive as procuring them.
Why Early T&I Input Matters
The influence of T&I considerations is greatest during the early development and concept design phases, when key decisions related to foundation type, geometry, weight, and installation philosophy are still flexible. At this stage, relatively small design choices—such as changes in diameter, length, segmentation, or tolerances—can have a disproportionate impact on the feasibility and efficiency of downstream construction activities. Once the foundation concept is frozen, the ability to address installation challenges becomes increasingly constrained and often requires costly mitigation measures.
Early T&I engagement supports the development of more realistic and robust project assumptions by providing technical and commercial scrutiny of the installation-related inputs used in early business cases. Reviewing assumptions related to vessel types, installation methods, weather windows, port availability, and construction strategies allows potential constraints to be identified before they are embedded in cost estimates and schedules. This process increases confidence in early CAPEX and schedule forecasts, particularly where limited data is available and uncertainty is inherently high.
At concept stage, early T&I input also enables the evaluation of multiple foundation type scenarios under a range of assumptions, including both optimistic and more conservative installation conditions. By assessing alternative concepts against realistic transport and installation constraints, developers can better understand sensitivity to key drivers such as vessel availability, soil conditions, environmental restrictions, and offshore execution limits. This approach supports a more transparent definition of risk allowances and contingencies within early budgets, rather than relying on generic or overly optimistic assumptions.
In addition, early T&I involvement helps define logistical and installation constraints that can directly inform both foundation designers and procurement teams. Clear guidance on feasible foundation weights, dimensions, handling requirements, installation tolerances, and preferred construction strategies provides a practical framework for design development and supplier engagement. Aligning these constraints early supports more informed decision-making during concept selection and early procurement discussions, while maintaining flexibility as the project matures.
Benefits of Early T&I Engagement
In practice, early T&I engagement can deliver the following benefits:
- Higher confidence in CAPEX and schedule assumptions used for investment decisions and bid submissions
- Reduced risk of contingency erosion due to more realistic installation strategies
- Lower exposure to late-stage scope changes and contract variations driven by constructability issues
- Improved cost competitiveness by avoiding conservative pricing driven by uncertainty
- More robust and defensible risk allowances within early business cases and bids
- Stronger alignment between design, procurement, and construction planning, reducing interface risk
- Increased schedule resilience through earlier identification of installation and logistics constraints
- Reduced likelihood of pre-FID capital commitments driven by late identification of port or infrastructure requirements
- Improved bankability and stakeholder confidence through clearer execution visibility
From concept to execution: A more integrated approach
Successful offshore wind projects increasingly demonstrate that integrating design and installation thinking from day one leads to better outcomes at execution stage. Early development effort – often perceived as additional DEVEX – can significantly reduce downstream CAPEX and execution risk by ensuring that foundation concepts are developed with realistic construction constraints and market conditions in mind. In this context, early T&I engagement is not an overhead, but a strategic input that enables more informed and resilient project decisions.
An integrated approach requires bridging the gap between concept design, procurement strategy, and offshore execution. Drawing on hands-on experience from field operations, combined with deep technical expertise and up-to-date market intelligence, early T&I input can translate high-level concepts into executable solutions. This includes understanding how designs behave during transport, lifting, and installation; how vessels and ports are actually utilized offshore; and how supply chain constraints influence cost, availability, and risk.
In parallel, early T&I involvement supports more informed commercial decision-making. By leveraging active relationships across the supply chain – including installation contractors, vessel operators, ports, and fabricators – market-driven insights can be incorporated into early assumptions. This helps developers understand not only what is technically feasible, but also what is commercially realistic, reducing reliance on optimistic assumptions and improving confidence in early budgets and schedules.
Through this integrated approach, installation-driven risks are identified and addressed when they can still be mitigated through design optimization, concept selection, or procurement strategy, rather than being absorbed later through cost escalation or offshore mitigation measures. The result is a smoother transition from concept to execution, with foundation solutions that are better aligned with both engineering intent and construction reality.
Conclusion
In conclusion, the evolving scale and complexity of offshore wind projects make early integration of transport and installation considerations more critical than ever. Decisions made during the initial design stages can have far-reaching impacts on constructability, cost, and risk, while early engagement allows these factors to be addressed proactively rather than reactively. By embedding T&I thinking from day one, project teams can develop foundation concepts that are not only technically sound but also execution-ready, enabling more confident planning, better-aligned procurement, and smoother transitions from concept to construction. Ultimately, projects that embrace this integrated approach are better positioned to manage risk, optimize cost, and unlock the full potential of offshore wind development.
Anders Præstholm Riisager
Head of T&I Strategy Development
T: +45 50 70 87 86
E: apr@bluepp.dk
Gabriel Félix Aguilera García
Foundation Installation Manager
T: +31 (0) 683521214
E: gfa@bluepp.dk
