Looking for the best construction project delivery method? Here's the short answer: Construction Manager at Risk (CMAR) often outperforms Design-Bid-Build (DBB) for complex or time-sensitive projects. Why? CMAR integrates the construction manager early during design, ensuring better cost control, faster timelines, and reduced risks. Meanwhile, DBB, a more traditional approach, separates design and construction phases, often leading to delays and unexpected costs.
| Criteria | CMAR | DBB |
|---|---|---|
| Risk Allocation | CM assumes risk via GMP | Owner bears risk from design errors |
| Cost Certainty | High; costs capped early | Low; costs finalized after design |
| Timeline | Faster; overlapping phases | Slower; sequential process |
| Collaboration | Integrated teamwork | Architect and contractor work separately |
| Best Fit | Complex, fast-paced projects | Simple, well-defined projects |
Bottom Line: If your project demands tight budgets, strict timelines, and early collaboration, CMAR is the way to go. For simpler projects with fewer variables, DBB may suffice.
CMAR vs Design-Bid-Build: Key Differences at a Glance
In the Construction Manager at Risk (CMAR) method, the construction manager (CM) gets involved early during the design phase, long before any actual construction begins. By collaborating with the owner and architect, the CM reviews designs to ensure they can be built efficiently, identifies potential cost issues, and starts planning procurement strategies while the designs are still evolving. This early involvement lays the groundwork for better risk management, tighter schedules, cost oversight, and improved teamwork.
One of the standout features of CMAR is how it handles risk. At the core of this approach is the Guaranteed Maximum Price (GMP). Once the GMP is set, the CM takes on financial responsibility for any costs that exceed it, shielding the owner from unexpected overruns. This marks a major departure from traditional contracting, where owners often bear the financial burden of design oversights or unforeseen challenges during construction.
"The construction manager on a CMAR build takes on the bulk of the risk for the project by providing the owner with a guaranteed maximum price (GMP)." - Procore
This risk-sharing model is especially valuable for large, complex projects. For instance, when material prices surge - sometimes climbing over 20% annually - the CM is responsible for managing those fluctuations within the GMP, ensuring the owner’s budget remains intact.
By engaging early, the CM helps resolve potential scheduling issues before they become on-site problems. Through constructability reviews, the CM identifies challenges, flags items requiring early procurement, and plans trade sequencing in advance. This proactive approach reduces the likelihood of change orders by 20–30%, which directly translates to fewer delays and a smoother timeline.
CMAR employs an open-book bidding process, allowing the owner to review subcontractor bids and cost breakdowns in detail. This level of transparency fosters trust and often reveals opportunities for cost savings. Additionally, the CM works with the architect on value engineering - suggesting alternative materials or systems that maintain the design’s intent while staying within budget. Without this early coordination, rework can consume up to 12% of total project costs. CMAR is specifically designed to catch these issues upfront, saving both time and money.
Unlike the Design-Bid-Build (DBB) model - where the architect and contractor rarely collaborate directly - CMAR fosters a strong partnership between the owner, architect, and CM from the very beginning. This integrated approach sets CMAR apart, particularly for high-stakes projects.
"With CMAR, the construction manager acts as an advocate for the owner on both design and construction phases of a project to ensure the costs remain below the guaranteed maximum price." - Jonny Finity, Content Manager, Levelset
Design-Bid-Build (DBB) is the most established project delivery method in the U.S. Its process is simple and linear: the owner hires an architect to design the project, opens bidding to contractors once the design is complete, and then awards the contract to the lowest bidder. Each phase must be completed before the next begins, making this a step-by-step approach. However, this structure often leads to delays and risks. Comparing DBB with CMAR highlights key differences in risk, timelines, cost, and teamwork.
In DBB, the owner takes on a larger share of financial risk compared to CMAR. Since the contractor isn't involved during the design phase, any mistakes or gaps in the architect's plans fall on the owner once construction begins. The contractor is only responsible for building exactly what's in the documents. If those documents are flawed, change orders are inevitable, and the extra costs are the owner's responsibility.
Next, let's look at how DBB impacts project timelines.
DBB is the slowest project delivery method. Because bidding can’t start until the design is fully completed, the timeline stretches considerably. Just the bidding and procurement process can take six months or more before construction begins. Phases cannot overlap, and there’s no chance to pre-order materials with long lead times, further extending the schedule.
Now, let’s see how these delays tie into cost management.
While competitive bidding might seem like a way to save money, it also means firm pricing isn’t established until the design phase is finished. During this lengthy design period, the owner must rely on fluctuating cost estimates, making budgeting more difficult. Additionally, without a construction manager involved in the design phase, opportunities for cost-saving measures - like value engineering - are often missed.
Finally, consider how DBB influences team dynamics and collaboration.
In DBB, the architect and contractor operate under separate contracts with the owner and have no direct relationship with each other. During construction, the architect’s role shifts to supervising the contractor’s work, which can lead to tension rather than cooperation. Standard contracts, such as AIA A101 and B101, reinforce this separation of responsibilities. For simple commercial projects where independent oversight is a priority, this setup might work well. But for more complex or fast-paced projects, this lack of integration can be a serious drawback. Early collaboration between key players becomes essential for projects with tight deadlines or high stakes.
Let’s break down the key strengths and weaknesses of each method, focusing on how they perform under different project demands. The choice between these approaches often comes down to balancing complexity, timelines, and financial predictability.
One major distinction lies in financial risk. With CMAR, the construction manager assumes responsibility for budget overruns once the Guaranteed Maximum Price (GMP) is set. On the other hand, DBB shifts the risk to the owner, who can face unexpected costs from design errors or change orders. Consider this: the average construction dispute in North America - frequently caused by DBB’s design gaps - can exceed $42 million and take more than 13 months to resolve.
Cost predictability also varies. CMAR provides tighter estimates, narrowing from ±10–15% during the conceptual phase to ±5–7% by pre-construction. In contrast, DBB doesn’t lock in pricing until the bidding phase, which happens after the design is fully completed, often months later.
"The fundamental principle behind CMAR is that the majority of cost and risk is determined before construction begins." - Pat Williams, CEO, Pat Williams Construction
Here’s a quick comparison of the two methods, highlighting their practical differences:
| Criteria | CMAR | DBB |
|---|---|---|
| Risk Allocation | The CM assumes risk for budget overruns via GMP | The owner bears risk from design errors and change orders |
| Cost Certainty | High; GMP caps costs early in the process | Low; final costs often exceed initial bids |
| Project Timeline | Faster; overlapping phases allow early procurement | Slower; sequential process - design, bid, then build |
| Contractor Input | Early involvement in design, materials, and sequencing | None until the design is fully completed |
| Team Dynamics | Collaborative, with integrated input | Separate; architect and contractor work independently |
| Best Fit | Suited for complex, multi-phase, or critical projects | Ideal for simple, well-defined projects |
While DBB remains a solid choice for public projects requiring competitive bidding and independent oversight, it often struggles with tight schedules and unpredictable costs. For projects where timing, budget control, and early collaboration are essential, CMAR tends to stand out as the better option.
Deciding between CMAR and DBB comes down to what your project demands. As discussed, CMAR stands out by offering early involvement, which helps maintain budgets, schedules, and fosters collaboration - areas where DBB often falls short.
The data shows that securing a Guaranteed Maximum Price early provides a strong financial buffer against market fluctuations. This highlights CMAR's reliability, especially in fast-moving and complex projects.
For critical projects like data centers, manufacturing facilities, or infrastructure, CMAR brings extra value through early constructability reviews and forward-thinking procurement strategies. When staffing for a CMAR project, it’s crucial to focus on Qualifications-Based Selection (QBS) rather than simply choosing the lowest fee.
Choose Construction Manager at Risk (CMAR) instead of Design-Bid-Build (DBB) when your project demands tighter schedule control, better cost management, and stronger team collaboration. CMAR brings the contractor into the process early, allowing for tasks like constructability reviews, value engineering, and proactive risk handling. This approach helps minimize delays and rework. For challenging, high-stakes projects, CMAR's integrated method delivers more reliable results, unlike DBB, which often struggles with inefficiencies and limited early control over costs and timelines.
The Guaranteed Maximum Price (GMP) in Construction Manager at Risk (CMAR) contracts is determined early through collaboration between the construction manager and the owner. This figure is based on the project's scope, cost estimates, and specific assumptions. However, the GMP isn't set in stone - it can shift due to changes in project scope, further design development, or misinterpretations about what the GMP covers.
When selecting a CMAR construction manager, focus on candidates who bring hands-on experience with mission-critical projects. It's essential they have expertise in systems integration and a deep understanding of various construction delivery methods. Prioritize individuals with a history of managing high-pressure environments and delivering projects successfully.
