Customer story: what happens when superintendents get survey-grade tools

Before a recent concrete pour, Colby Lindsay walked the site and checked the anchor bolts. Every one of them sat about 6 inches out of position. He caught it before the pour—before the steel arrived and nothing lined up, and before the crew chased a fix that would have cost far more than the receiver in his hand.

“That right there paid for the unit,” he says, “and probably could have paid for 10 more.”

Lindsay is a virtual construction manager and BIM coordinator at CORE Construction, and his team’s version of that routine is to catch problems earlier. Over the past few months, they’ve put field GNSS receivers from Emlid, accurate to the centimeter, into the hands of superintendents and project engineers. 

The bet: let the people closest to the work check it themselves, while there’s still time to fix it.

Key takeaways

• Anchor bolts sat 6 inches out of position. Catching it before the pour saved far more than the receiver cost.
• Drones cover the whole site but can’t verify a 1-inch anchor bolt or a plumbing stub-up. That gap is where GNSS comes in.
• GNSS gives superintendents a middle step: check a layout in minutes, then decide if it’s worth calling a surveyor.
• The receiver data isn’t the official survey. It’s a double-check that sharpens the call on when to bring in a surveyor.
• Data-backed questions cut months of back-and-forth with trade partners down to a single conversation.
• Emlid Flow, DroneDeploy, and Flow 360 stay connected, so field data reaches the office without manual file transfers.

A company built around quality control

CORE Construction is a general contractor working across K-12 schools, healthcare facilities, and municipal and civil projects in California, Nevada, Arizona, Idaho, Texas, Indiana, Illinois, and Florida. A lot of that work is renovation: new buildings on existing campuses, new utilities tying into old ones. When you’re building on top of what’s already there, getting it right the first time matters more.

The company runs a dedicated Virtual Construction department to support that. Danielle Williams directs it, leading virtual construction managers across the country and setting the tools and procedures the field teams use. Lindsay handles BIM coordination, flies the drones, and spends a lot of his week in the field.

“That’s why we like to get in front of them,” Williams says of the field teams. Site visits are how her group finds the things worth solving:

It’s just what we’re seeing our field teams encountering, what they’re having the most quality control issues with. That’s what drives us to look for new technologies.
– Danielle Williams

CORE Construction models its quality control on the Army Corps of Engineers approach: a pre-work meeting with each trade partner, a first inspection when the first piece of work goes in, and follow-up inspections as the work continues. The receivers fit into the initial and follow-up steps of that process.

The data gap drones couldn’t close

The team had been flying drones for years. From the air, with ground control points (GCPs) set out below, a drone gives you clean topography and the shape of the whole site. What it can’t give you is a 1-inch anchor bolt.

When you’re trying to verify anchor bolts for connections to steel columns, those are like 1-inch bolts. From 100 feet in the air, you can’t get that close of imagery on it.
– Danielle Williams

The same went for plumbing stub-ups that had to land inside a wall. That left a familiar gap. The drone could tell the team something looked roughly right, but it couldn’t confirm the details. So when steel arrived, and the anchor bolts didn’t line up, the team would find out late, and the schedule would feel it.

In construction, the cheapest mistake is the one you catch early. The expensive ones surface weeks later as rework, and the usual culprit isn’t bad workmanship; it’s the wrong information reaching the field too late. 

A 2025 PlanRadar survey of more than 800 construction professionals found that firms with consistent quality control were far likelier to keep rework under 5% of budget: 56%, against 37% of those without.

There were two ways to close the gap, and neither was free. Measure everything by hand, which results in unreliable data. Or call in a surveyor, which costs money and means waiting on someone else’s availability.

Related reading: Discover why you need to use ground control points (GCP) for drone mapping

The check before the surveyor calls

CORE Construction keeps licensed surveyors on every project, but asking a surveyor to step outside their scope adds cost every time. Bringing surveying fully in-house wasn’t practical either, given the licensing it requires.

So the team looked for something to sit between the rough picture and the surveyor call. GNSS receivers running RTK (real-time corrections that lock in centimeter accuracy on the spot) turned out to be that something. The team chose Emlid’s Reach receivers. A superintendent can now walk over with GNSS, check a layout, and decide then and there whether it’s worth a surveyor call.

It’s a good secondary option to identify if we have a problem, and then we can call a surveyor in, it’s kind of like a step in between.
– Danielle Williams

That boundary matters. CORE Construction doesn’t build off the receiver data or treat it as the official survey. It’s an in-house double-check that gets everyone on the same page before anyone makes a decision. 

The change is still real: the team went from telling a project manager “you might have a problem, but we’re not sure—go measure it yourself” to “you definitely have a problem here.”

Better questions, faster answers

The verification is half the value. The other half is the conversation that makes it possible.

CORE Construction brings the survey information and the trade partners’ uploaded drawings into Emlid Flow, the field app, geolocated on the same map. So the office, the field, and the subcontractors are all reading from the same reference. When a superintendent who understands that data walks up to a trade partner, the exchange gets shorter.

So many times I’ve asked a more educated question, and I get exactly what I need right away, versus them asking for it for months.
– Colby Lindsay

That’s the part a general contractor feels across every trade on the job. A sharper question, backed by data everyone can see, ends a back-and-forth that used to stretch across weeks. The trade partners spend less time troubleshooting and more time building.

Putting GNSS in the field crews’ hands

Lindsay handpicks the people he thinks will get the most from a receiver—usually the superintendents already feeling the pain—and walks it out to them himself. Often, he just uses it for them for the first time. That’s typically all it takes.

The company is now using several units of the Reach RS3, RS4, and RS4 Pro receivers and treating the current stage as a beta, on purpose, across three regions to gather a range of feedback. In Texas, it’s mostly superintendents and assistant superintendents. An Arizona team running off-site street work that would otherwise have called for a total station is using GNSS instead. A team in Reno is putting it to work alongside commissioning. Around seven teams are in the field as of May 2026.

The tools also talk to each other, which keeps the picture coherent. CORE Construction moves data between Emlid and DroneDeploy as DXF files. 

It recently pulled its DroneDeploy imagery into Emlid Flow as a map layer, so the same drone capture that shows the big picture sits underneath the centimeter-level checks. And because the projects sync through Flow 360, a point a superintendent collects in the field reaches the office without anyone emailing a file around.

Related reading: check this customer story on how to run an accurate drone mapping with an Emlid Reach RS4 Pro base

Scaling up: From field beta to standard operating procedure

As CORE Construction moves through the summer of 2026, Williams plans to aggregate data from the multi-region beta to formalize the program. The ultimate goal isn’t just deploying more hardware, but establishing a standardized framework—defining clear internal criteria for exactly when, where, and why a GNSS receiver earns its place on a jobsite.

It’s part of a bigger trend in construction tech: moving accurate data out of the back office and straight into the field. By putting these tools directly into superintendents’ hands, general contractors can catch costly mistakes early without slowing down the schedule.

For CORE Construction, the days of guessing or waiting around for an outside surveyor are over. A superintendent can now spot a potential issue, check it in minutes, and move forward with data-driven confidence. Catching a massive error before the concrete pours isn’t a stroke of good luck anymore—it’s just the workflow.

Want this kind of quality control on your jobsite? See how Emlid’s GNSS receivers fit into construction workflows, from layout checks to as-built verification.

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