Creating Your Primary Control Plan In Construction

Creating Your Primary Control Plan in Construction

In this blog, we’re diving into the critical step of creating your primary control plan—the foundational system that guides all layout and survey work on your project. If you’ve already seen our previous blog on getting coordinates and verifying your basis of bearings, this is the perfect next step.

Once you’ve locked down your coordinates and verified the property corners with contract surveyors, it’s time to begin developing the primary control plan. This is the intermediate step between your pre-construction survey prep and your boots-on-the-ground layout activities. Think of this as the bridge between design and field execution.

Getting on the Same Coordinate System:

One key lesson: everything must be on the same coordinate system. Whether you’re using state plane or geodetic coordinates, consistency is non-negotiable. Mismatched coordinate systems can cause serious layout issues, like what happened on a project in Austin, Texas. Make sure the basis of bearings, property corners, and building points all match exactly.

Building the Primary Control Plan:

The current plan lives in AutoCAD and includes:

• Verified basis of bearings.
• Verified property corners.
• Points for each building.

We’re now moving into creating baselines for each building using grid line intersections. From these, primary control points will be laid out around the project site. The field engineer or surveyor will use total stations to backsight and forward shoot across these points, verifying their accuracy using direct and reverse shots. This setup allows for precise 90-degree turns and accurate layout of any building element.

What the Final Plan Looks Like:

We’re aiming for a complete primary control file that includes:

• Coordinates for all points.
• Distances and azimuths.
• Elevations where necessary.
• Clear grid layouts and secondary baselines.

Everything will be prepared and aligned in AutoCAD, and we’re well on our way to a fully controlled site.

Surveyor Scope Is Key:

None of this works without the right scope for the surveyor. That includes:

• A full boundary survey.
• Verification of the basis of bearings.
• Property corner validation.
• Monument layout for control points.
• As-built certifications.

When you combine this with a clear interface between the surveyor and the field engineer, your project is set up for success.

Final Thoughts:

Our CAD files are nearly complete. The monuments are about to be set. Once everything’s posted in the office trailer and installed in the field, we’ll revisit this topic with a final walkthrough. Until then, I hope this blog gives you a solid foundation for understanding and building your own primary control plan.