Publication Date: 10/16/26

Constructability Review: What It Is and Why It Matters

By Frank Abbott | Summit Preconstruction Consultants

A set of site plans can show the correct drainage layout, utility connections, grading, pavement limits, and landscape improvements and still leave important questions about how the work will actually be built.

The individual details may be correct. The quantities may be accurate. The finished improvements may fit within the available property.

But construction does not happen all at once, and it does not happen under the conditions shown on a finished site plan.

Excavations require working room. Equipment and materials need access. Existing utilities have to be protected or worked around. Grades change as the project progresses, and areas needed for one operation may be occupied by another.

A proposed drainage line may fit neatly between an existing building and a property line. That does not necessarily mean there is enough room for the excavation, trench protection, equipment, and material handling required to install it.

These are the conditions that need to be considered before construction begins.

That is the purpose of a constructability review. It examines the design from the perspective of the work that must be performed, not simply the improvements that will exist when the project is complete.

A constructability review is an evaluation of the proposed work to identify conditions that could affect how the project is built.

It goes beyond checking whether the drawings contain the necessary information. It considers whether that information reflects the practical requirements of performing the work under the conditions expected on site.

For site and civil projects, that means looking closely at existing grades, underground utilities, drainage systems, excavation requirements, site limitations, and the relationship between different construction activities.

The review also considers whether the drawings and specifications provide enough information for contractors to develop a reasonable understanding of the work before committing to a price.

This is not the same as checking quantities or performing a conventional estimate.

An estimator may determine that a project requires a certain amount of excavation, several hundred feet of drainage pipe, a specific quantity of aggregate, and a defined area of pavement. Those quantities establish part of the cost, but they do not tell the entire story.

The excavation still has to be performed. The pipe has to be installed at the required elevations. The aggregate must be placed and compacted, and the finished grades need to tie into the surrounding property.

Each operation has physical requirements that may not be obvious from the quantities alone.

A constructability review looks at those requirements and considers whether there are conflicts, limitations, or unanswered questions that should be addressed before construction begins.

The objective is not to redesign the project or tell the contractor exactly how to perform the work. It is to identify potential construction concerns and bring them to the appropriate people for evaluation.

One of the more common problems I have encountered over the years involves existing underground utilities.

There have been numerous occasions when utilities were located and marked before excavation, only to discover that the lines were not actually where the markings indicated. In other cases, we discovered utilities installed considerably shallower than expected or at depths that did not match the information available during planning.

These conditions can change an excavation operation quickly.

A crew may be working from a set of plans that shows adequate separation between an existing utility and a proposed drainage line. The utility has been marked, the excavation has been planned, and the anticipated installation appears straightforward.

But once the existing line is exposed, the actual location or depth may create a conflict that was not apparent during planning.

Now the operation may require additional investigation, coordination with the utility owner, or clarification from the engineer before work can proceed.

These situations become more complicated when several utilities occupy the same general area.

Storm drainage, sanitary sewer, water services, electrical conduits, and communications infrastructure may all need to fit within a relatively limited underground corridor.

Each system may be shown correctly on its respective drawing, but that does not necessarily mean the actual field conditions will match the information available during design.

Existing utility locations may have been developed from record drawings, available surveys, or other information that does not fully establish their actual horizontal position or depth.

This is where construction experience becomes valuable during preconstruction.

An experienced reviewer understands that existing utility information is not always complete or accurate. Where proposed improvements depend on critical utility crossings or limited clearances, the review should identify whether additional verification is warranted before bidding or construction.

A constructability review cannot uncover every underground condition. Even with proper locating procedures, unexpected conflicts can still develop once excavation begins.

But it can recognize where the project is relying on assumptions that deserve closer examination.

The objective is to address those uncertainties before crews and equipment are committed to an operation that may not be practical under the actual conditions.

Grading plans deserve particular attention because so much of a site development project depends on getting the elevations right.

The plans may establish finished grades, drainage structures, pavement slopes, and elevations where new improvements connect to existing conditions.

But those finished elevations are only one part of the work.

A contractor also has to consider the excavation required to reach the proposed subgrades, the materials needed to build those grades back up, and how the different surfaces and drainage improvements will fit together.

A proposed pavement elevation may work at one location but create difficult transitions near an existing entrance, curb line, drainage structure, or adjoining property.

A drainage structure may be shown at an appropriate finished elevation, while its installation requires excavation below surrounding grades or in an area where groundwater or existing utilities could complicate the work.

None of those conditions automatically means the design is incorrect.

They do mean that the proposed work deserves a closer look before construction begins.

Grading also changes throughout the project.

During earthwork, the site may bear little resemblance to the finished grading plan. Excavation areas, temporary slopes, drainage paths, stockpiles, and areas awaiting aggregate or pavement can all influence how the property functions while construction is underway.

Temporary drainage and erosion control measures need to be considered alongside those changing conditions.

A design that properly addresses the finished project should also provide sufficient information for the project team to understand important construction-phase restrictions and requirements.

Experienced sitework personnel understand that the finished grades are the destination. Getting the project to those grades requires a workable series of operations.

Constructability concerns are not limited to underground work.

Retaining walls, curbing, pavement, sidewalks, site lighting, and landscape improvements all have installation requirements that can affect other portions of the project.

A retaining wall is a good example.

The plans may identify the wall location, foundation requirements, drainage, and backfill. But the construction process may require excavation beyond the limits of the completed wall, temporary support, and working space for equipment and material placement.

If the wall is close to a property line, existing pavement, or another improvement, those requirements become particularly important.

The same principle applies to landscape construction.

Planting plans may show trees, shrubs, landscape beds, and finished lawn areas without making every underground conflict immediately apparent.

A proposed tree location may interfere with a drainage line, underground electrical service, or another utility corridor. A landscape bed may occupy an area needed for access to a drainage structure. Irrigation improvements may need to be coordinated with grading, utilities, and pavement construction.

Those relationships should be considered before installation begins, not discovered after other improvements are already in place.

Sequence is another important consideration.

Sitework usually progresses through a series of related operations. Clearing, earthwork, utilities, drainage, grading, aggregate placement, curbing, paving, and landscape restoration must be coordinated with one another.

The exact order depends on the project, but the relationship between those activities matters.

Completing one improvement too early can interfere with another operation that still needs access or working room. Delaying a necessary activity can prevent subsequent work from progressing.

A constructability review examines those relationships to identify where coordination or clarification may be necessary.

It does not need to establish every daily activity that will occur during construction. That level of planning is generally part of the contractor's responsibility.

What it should do is identify design-related conditions and project restrictions that could significantly influence the way the work must be organized.

A constructability review should begin with a thorough understanding of the available project information.

That includes the plans, specifications, existing-condition information, geotechnical reports where available, and any restrictions or requirements established by the owner.

The drawings need to be examined together rather than treated as separate pieces of information.

A utility detail may need to be compared against the grading plan. Drainage profiles may need to be reviewed alongside existing conditions. Proposed landscape improvements should be checked against underground utilities and other site features.

The reviewer should also look for inconsistencies between the drawings, specifications, and scope requirements.

A construction detail that conflicts with a specification can create uncertainty about materials or installation requirements. A missing limit of work can affect quantities and restoration responsibilities. Unclear information about existing conditions may create assumptions that bidders cannot reasonably verify.

For projects involving existing developed properties, a site visit can provide important context.

A set of plans may not fully communicate the limitations created by existing improvements, surrounding operations, changes in grade, or the available working area.

Walking the property with the drawings provides an opportunity to compare the proposed work against observable site conditions.

However, a site visit cannot establish everything. Underground conditions, subsurface materials, and concealed infrastructure may still require investigation or confirmation by qualified professionals.

When information is unavailable, it should be identified as an uncertainty rather than treated as an established fact.

Most importantly, the review should produce useful findings.

Simply identifying a possible conflict does not accomplish much unless the concern is clearly explained.

If the proposed drainage layout appears to interfere with an existing utility, the review should identify the location, explain the potential problem, and establish what information or decision is needed to resolve it.

Some concerns may lead to revised plans. Others may require an additional investigation, clarification from the design team, or confirmation that the original design is appropriate.

A useful review gives the project team an opportunity to address those concerns before they turn into field problems.

For owners and contractors, one of the most important reasons to evaluate constructability is the effect unresolved construction requirements can have on project pricing.

Two contractors can review the same plans, measure the same quantities, and arrive at different estimates because they anticipate different approaches to performing the work.

That is not unusual.

Contractors have different equipment, crews, production capabilities, and experience. Those differences naturally influence how they approach a project.

The concern arises when the documents leave important construction conditions open to interpretation.

Suppose a project includes installing a drainage system through an area with several existing underground utilities.

One contractor may anticipate conventional excavation and normal production. Another may recognize that utility conflicts or working-space limitations could require additional effort and allow for that in the estimate.

Both may have accurately measured the pipe and drainage structures.

The difference is in the work they expect will be required to install them.

For an owner reviewing bids, that difference may not be immediately apparent.

A lower proposal does not necessarily mean a contractor overlooked something, and a higher proposal does not automatically mean the work has been more thoroughly evaluated.

However, when significant construction uncertainties exist, the owner should understand whether those conditions have been adequately addressed in the documents and reflected in the proposals.

A constructability review can identify questions that should be resolved before bidding, providing a clearer basis for contractors to price the work.

For contractors, that same information supports more realistic production assumptions, scope development, and evaluation of project risks.

This does not eliminate every difference between estimates or guarantee that construction will proceed without changes.

It helps establish a better understanding of the work before pricing decisions become contractual commitments.

One of the difficulties with reviewing constructability late in a project is that many of the important decisions have already been made.

Site layouts may be established, utility alignments selected, grades developed, and permit requirements incorporated into the design.

At that point, identifying a construction concern may require revisiting decisions that affect several other parts of the project.

Earlier in design, there may be more opportunity to evaluate those concerns and consider practical alternatives.

A utility alignment might be reviewed before it becomes part of a completed site design. A retaining wall location could be examined with the necessary construction space in mind. Grading and drainage decisions may benefit from reviewing how the site will be excavated, filled, and brought to its finished condition.

That does not mean construction personnel should take over the design process.

Engineers remain responsible for their professional design decisions, and contractors remain responsible for their applicable construction means and methods.

The value comes from bringing different perspectives into the discussion.

The designer understands the technical requirements and intended performance of the improvements. The contractor understands the practical demands of installing them. The owner understands the property's operational needs, project objectives, and financial considerations.

An independent constructability reviewer can help identify where those perspectives need to be brought together.

For projects where construction experience has not been involved during design, that independent review can be particularly useful before the owner proceeds to bidding.

The review should be appropriate to the project. A small parking lot improvement may not require the same level of evaluation as a complex municipal utility reconstruction or a major commercial site development.

The important consideration is whether the project has been examined closely enough to identify reasonable construction concerns before they become more difficult to address.

There will always be conditions that cannot be fully anticipated before construction begins.

Underground utilities may not be located exactly where records indicate. Subsurface conditions may differ from available information. Weather, delivery schedules, and other factors can affect the work.

Those are realities of construction.

But there is a difference between encountering an unexpected condition and discovering that an obvious construction requirement was never adequately considered.

A utility crossing with questionable clearances, a retaining wall with limited working space, an unclear grading transition, or conflicting requirements between drawings and specifications may present concerns that can be identified before construction begins.

Recognizing those concerns gives the project team an opportunity to evaluate them while there are still reasonable options available.

For owners, a constructability review provides another level of understanding about what the proposed improvements may require and where uncertainties could affect pricing or execution.

For contractors, it supports clearer scope interpretation, more realistic estimating, and better preparation for the actual work.

The purpose is not to guarantee that a project will be free of problems. Construction will always require experienced people making decisions as conditions develop.

The purpose is to address the concerns that can reasonably be identified before they consume labor, equipment time, and project resources.

A good set of plans establishes what needs to be built. Good preconstruction considers what it will take to build it.

Clarity Before Construction.

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Frank Abbott is the founder of Summit Preconstruction Consultants, providing practical preconstruction support to owners, developers, property organizations, and contractors throughout New Hampshire.

With more than 45 years of experience in the construction industry, Frank has worked extensively in field operations, project management, and general management. His background includes overseeing multiple projects and coordinating crews, equipment, budgets, and operations across landscape construction, site development, civil construction, and municipal projects.

Through Summit, he applies that hands-on experience to scope evaluation, budgeting, constructability reviews, bid support, and early identification of project risks. His approach focuses on connecting design and preconstruction decisions with the practical realities of building the work.