9 questions i ask during constructability
A constructability review is about a lot more than running clash detection.
It’s about knowing WHAT to look for.
Before a single coordination meeting ever happens, these are the 9 critical questions I ask during a comprehensive 2D/3D constructability review:
1. Are the drawings aligned between each trade?
This one is so simple, yet so important. If the grid lines don’t match up, then there’s going to be some major issues. Do the electrical and mechanical plans show the exact same grid layout as the architectural sheets? If not, you're guaranteed to have major RCP issues.
2. Will underground utilities conflict with foundations?
This is one of the highest cost and schedule risks on a project. First, I verify invert elevations for gravity pipes. Does it work with the tie-in point? Do we have enough fall from the farthest fixture? Once that’s verified, it’s all about footings. Catching waste lines, storm drains, duct banks, and conduit routes that intersect footings before concrete work begins saves significant time and money.
3. Where are current routings flat-out not constructable?
The design model might look clean on paper, but physics applies in the field. Once you factor in duct and pipe insulation, hangers, dampers, and structural tolerances, will it actually fit? Look for red flags like a duct main routed parallel through the entire length of a wall (or right through king studs), or a vent line crossing the entire building where you know another vent-to-roof (VTR) needs to be added.
4. Where do we have issues with openings & penetrations?
When you look at architectural elevations, everything looks flawless. But when you overlay the structural and MEP models, openings are often a total war zone. Louvers, windows, roof hatches and curbs, love to fight with structural steel. Or if the project is CMU-heavy, systems are often shown plowing through a bond beam or vertical rebar. Looking for these issues is always part of my process.
5. Can we achieve equipment clearances and requirements?
AHUs, VAVs, valves, dampers, electrical panels...if someone can't access it after construction, you’re going to have problems. Are valves accessible? Can someone get to the fire damper? Is the mechanical room too small for real-world coil pulls? Does the medium pressure duct have enough straight run to the VAV? Are the pull boxes accessible? Although we’re often working with generic "basis-of-design" models at this stage, we can easily anticipate where these bottlenecks will happen.
6. Where do we need to address issues with structural steel?
Sometimes these conflicts are painfully obvious, like when we have floor-mounted fixtures sitting directly above a structural beam. Sometimes, it’s less noticeable, like the way the AHU orientation doesn’t work with the bar joists. Or maybe you have HSS going through a wide louver and nowhere to move it. If these issues aren’t addressed before steel fabrication, your options become much more limited.
7. Where are ceiling heights a concern?
Just because an MEP system fits on a 2D drawing doesn't mean it fits in real life once you factor in insulation, slope, and structural tolerances. Corridors and lobbies are notorious for limited plenum space. Sometimes the beam is deeper than the ceiling, allowing nothing to cross. Other times, there appears to be enough space, but system are all competing for the same elevation. I evaluate the exact space between the ceiling and the bottom of steel to discover these pinch points early.
8. Will architectural features create installation issues?
Soffits, casework, roof hatches, exposed steel, specialty ceilings, and lighting layouts often require MEP systems to be redesigned long before coordination starts. Does the ceiling type allow for access to dampers and valves? Is the wall type wide enough to accommodate plumbing stacks? Are there MEP or ceiling conflicts with door transoms? These are usually the issues that take more than clash detection to find.
9. What information is still missing?
Sometimes the biggest constructability issue isn't a clash, it’s the data gap. It’s helpful to identify the “known unknowns” early, like waiting on equipment submittals, sprinkler layouts, steel shop drawings, or existing condition verifications.
The best constructability reviews don't just identify problems.
They give the design team time to solve them while changes are still inexpensive.
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