Engineering Plan and Spec:
How Traditional Project Delivery Works in Commercial Construction
If you work in MEP design and construction for commercial buildings, you’ve likely heard the term plan and spec. You might encounter it when a job is labeled a plan and spec job, or when discussing a new opportunity that’s described as a plan and spec bid. The term is common in the industry, but if you’re just starting out, the meaning may not be immediately clear.
What Does Plan and Spec Mean?
Plan and spec refers to a commercial construction project delivery method in which design drawings (plans) and written specifications (specs) are created to define the equipment and components of the project.
You might also hear this method referred to by other names—planning and specifications, plan-spec, or P&S. Other interchangeable terms include design-bid or design-bid-build. While the names vary, they all describe the same delivery method.
At the start of every construction project, the Owner chooses the project delivery method. Plan and spec remains the most traditional approach, though newer methods like design-build are growing in popularity. Each method offers unique benefits and challenges. The primary difference lies in how team roles align and when construction begins.
What a Plan and Spec Project Typically Looks Like
While no two projects are exactly alike, plan and spec jobs usually follow a similar structure in terms of team organization and project phases.
In a plan and spec project, the Owner hires two separate teams:
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Design Team – This team typically includes MEP engineers, civil and structural engineers, architects, and other specialized consultants.
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Construction Team – This group includes the general contractor and subcontractors like the mechanical contractor.
The Owner may also bring in independent consultants outside of these two core teams. For instance, they might hire a commissioning agent to inspect construction work or bring in a third-party design review team before approving the final design.
Team Leadership and Communication
Each team operates under a lead consultant, known as the prime consultant. This person leads their respective team and manages communication with the Owner.
Traditionally, the architect serves as the prime for the design team, and the general contractor leads the construction team. However, this isn’t a strict rule. For some projects, the MEP engineer might act as the prime, with the architect in a supporting role.
Since the Owner contracts each team separately, the prime consultant on each side becomes the main point of contact and assumes two responsibilities: managing their own discipline and coordinating project-wide communication.
Team Responsibilities
In a plan and spec project, team responsibilities are clearly defined.
The design team produces a complete set of construction documents. The construction team then uses those documents to build the project according to specifications.
Project Phases
Plan and spec projects involve two principal phases: the design phase and the construction phase. Construction doesn’t begin until the design team completes and delivers the construction documents.
Each main phase includes smaller sub-phases. During the design process, for example, the team hits key milestones such as schematic design, design development, and construction design.
Pros and Cons
Like any delivery method, plan and spec has both advantages and drawbacks.
Advantages
Many Owners choose plan and spec because it offers more defined construction costs. After the design team finalizes the construction documents, the Owner can solicit bids. In simple terms, the Owner asks construction teams to quote a price based on the complete design. Knowing the cost before breaking ground helps Owners control risk and plan budgets more effectively.
Other benefits include:
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In-Depth Design and Analysis – Because construction begins only after design is complete, the design team has more time for thoughtful analysis and refinement.
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Design Collaboration – This method promotes strong collaboration between design disciplines, allowing for more integrated and optimized solutions.
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Creative Problem-Solving – Without construction deadlines looming, the design team has the flexibility to explore more innovative approaches.
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Specialty Projects – Plan and spec works well for complex, first-of-its-kind, or highly architectural buildings like net-zero energy projects.
Disadvantages
Every delivery method has trade-offs, and plan and spec is no exception.
Many construction professionals criticize plan and spec because it doesn’t always benefit their bottom line. Since they must deliver the project for a fixed bid, any delays or complications eat into their profit. Naturally, contractors often favor delivery methods that offer greater profitability—even if plan and spec is a better fit for the project.
Other disadvantages include:
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Longer Timelines – Plan and spec projects often take longer to complete. Even a “fast” one may take 1.5 years, while others can stretch to five years or more. This method may not suit projects that need rapid delivery.
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Disputes Over Construction Issues – No design is perfect, and issues inevitably arise. When they do, the Owner will want to assign responsibility. This can lead to disputes between the design and construction teams.
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Quality Risks from Low Bids – Owners sometimes award projects to the lowest bidder. While not always true, low bids can result in lower-quality workmanship if contractors cut corners to maintain profit margins. The building may not perform as the design team intended.
RWB’s Approach
At RWB, we deliver uncompromising quality on every plan and spec project. For more than 30 years, our team has specialized in high-performance mechanical, electrical, and plumbing design. Our experience, attention to detail, and dedication to continuous learning make us a trusted partner for commercial projects across Texas.
