How Drawing Review Caught Plumbing Gaps on a Minneapolis Preschool
- Child-toilet rough-in missed the casework, classroom outdoor air did not match the HVAC schedule, and kitchen floor drains did not sit under the equipment.
- Helonic checked the 86-sheet preschool PDFs for plumbing, airflow, and equipment locations.
- The engineers confirmed 214 issues and priced $90,000 in plumbing and HVAC rework they caught before permit.
Minneapolis, MN. 214 issues on 86 sheets.
Issues Detected
214 on 86 sheets
Lead Findings
Plumbing, air, drains
Estimated Savings
$90K before permit
Toilet Rough-In Missed the Casework
A mechanical and plumbing engineering firm was sealing a one-story preschool in Minneapolis. The set was 86 sheets. Classrooms, a kitchen, and child toilets shared the same wing.
The plumbing rough-in for the child toilets landed inside the casework zone on the architectural elevations. The HVAC schedule listed outdoor air for the classrooms that did not match the diffuser callouts on the plan. Kitchen floor drains sat beside the equipment, not under the sinks the food-service plan showed.
Those three items are a field core, a rebalance, and a saw-cut slab if they wait until the toilets and the kitchen equipment are set.
Helonic Checked Plumbing, Outdoor Air, and Floor Drains
They uploaded the permit PDFs. Helonic compared the toilet rough-in with the casework, the outdoor-air schedule with the classroom plan, and the floor drains with the kitchen equipment layout.
It listed 214 issues. The ones that repeated were the toilet rough-in inside the casework, the HVAC outdoor-air mismatch, and floor drains off the equipment plan.
The rough-in clash was the one that would have come back as a permit correction. The drains would have been a slab cut.
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214 Issues, $90,000 Caught Before Permit
The engineers moved the toilet rough-in clear of the casework, matched the outdoor-air number to the plan, and shifted the floor drains under the sinks before issue.
They put the avoided field work at $90,000. That was core drilling the toilet wall and cutting the kitchen slab after the pour.
The building department commented on the kitchen hood make-up air. It did not comment on the rough-in or the floor drains.
“The toilet rough-in sat in the casework, the outdoor air did not match the schedule, and the floor drains missed the sinks. Helonic caught those on 86 sheets before we submitted.”
Frequently asked questions
What did the preschool check cover?
Plumbing rough-in against casework, HVAC outdoor air against the classroom plan, and kitchen floor drains against the equipment layout.
How big was the drawing set?
86 sheets. Helonic listed 214 issues.
Does this name the school?
No. It says Minneapolis and preschool. The district and the street are not on the page.
Can a small set still justify the check?
On this job the rough-in and the floor drains would have been a slab and wall repair after the pour. The sheet count was low. The repair was not.
Manas Gandhi
Co-founder & CTO, HelonicManas is the co-founder and CTO of Helonic, where he leads engineering and AI research for construction drawing analysis. He works directly with structural, MEP, civil, and fire protection engineers to translate the way they review drawings into AI systems that flag the issues that actually matter in the field. Before Helonic, he built machine learning pipelines for technical document understanding and has spent the last several years interviewing licensed design engineers and discipline leads to ground product decisions in real practice rather than industry assumptions.
- AI for technical document understanding
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How this page was researched: Reviewed against Helonic's 2026 drawing-analysis categories, RFI workflow, and product capabilities.
Last reviewed by Manas Gandhi · September 16, 2026