When you’re trying to move a project forward, few things are more frustrating than hitting a snag at the permitting office. We know how small oversights in MEP (mechanical, electrical, plumbing) design can slow approvals and cost both time and money. The good news: with careful planning and code-compliant drawings, most delays are completely avoidable.
Here are the five most common code issues that trip up building permits — and how we prevent them for our clients.
1. Incomplete Load Calculations
The problem: Many submissions skip detailed HVAC or electrical load calculations, or they provide only rough estimates. Permit reviewers flag this immediately, since it affects system sizing and safety.
Our approach: We run full mechanical and electrical load calculations for every project, using software that complies with ASHRAE and NEC standards. This not only satisfies reviewers but also helps right-size equipment and avoid overspending.
2. Missing or Incorrect Ventilation Rates
The problem: Local and international codes (like the International Mechanical Code) set strict requirements for fresh air, exhaust, and ventilation. Missing those numbers in drawings often results in rejection.
Our approach: We verify ventilation rates against the latest IMC and local amendments for each jurisdiction. Every drawing set clearly labels airflow and ventilation requirements so reviewers don’t have to guess.
3. Undersized Electrical Service
The problem: In fast-moving projects, it’s tempting to assume the building’s electrical service will be adequate. If the service is undersized, the permit office won’t sign off.
Our approach: We calculate full building demand, check panel schedules, and coordinate with the utility provider if upgrades are needed. Our drawings show clear service sizing and breaker details, which helps permits move quickly.
4. Plumbing Code Conflicts
The problem: Plumbing codes vary by jurisdiction, and small mistakes — wrong slope on a drain line, missing cleanouts, improper venting — can derail approvals.
Our approach: We design to IPC or UPC as required, then double-check against local amendments. Our plumbing riser diagrams make code compliance obvious for reviewers, reducing questions and back-and-forth.
5. Fire Protection & Egress Overlooked
The problem: MEP designs that don’t account for fire protection systems, smoke control, or egress lighting can be bounced back by reviewers. These items are critical for life safety.
Our approach: We coordinate early with fire protection engineers and integrate life-safety systems into our MEP drawings. Emergency lighting, exit signage, and fire-rated penetrations are detailed so there are no surprises.
How We Keep Projects Moving
The permitting process doesn’t have to be a roadblock. At CAPCo, we’ve built our workflow around clean, code-compliant drawings that reviewers trust. By addressing these common issues up front, we help our clients:
- Reduce costly resubmissions
- Speed up permit approvals
- Start construction faster
If you’re planning a new project or retrofit and want to avoid permit headaches, let’s talk. We’ll make sure your MEP drawings are ready the first time.
— Chris Pieper, Principal Engineer
CAPCo Engineering