PermitVent provides building pros the necessary drawings and calculations to ensure IRC attic ventilation compliance.
PermitVent runs the IRC R806 net free area calculation — 1/150 or 1/300 — and the matching ventilation drawing, for the standard, traditionally insulated vented attics production builders put on nearly every house. The same package covers custom homes using traditional insulation in any community where these calculations and drawings are required as part of the permit set. In fact, IRC compliance is required regardless of building location for any residential home in the US with a vented attic. A properly ventilated attic inhibits mold growth and lowers operating cost for the homeowner.
Let us handle your attic ventilation calculations and drawings so you can focus on your specialty.
Services
We service everything from a simple individual roof plan to large libraries with multiple roof options.
Ventilation calculations
Net free ventilating area sized to the actual attic, with the ratio selection worked out for you.
- 1/150 or 1/300 ratio, with the conditions for each documented
- Intake / exhaust split (40–50% low, balance high)
- Vent product NFA cross-referenced to manufacturer data
Ventilation drawings
A roof plan marked up with vent locations and counts, ready to attach to the permit set — built to run across a builder's plan set, not just one house.
- Soffit and ridge/gable vent placement
- Baffle callouts at eaves
- Formatted to match your jurisdiction's submittal requirements
How it works
Send the attic info
Roof plan or sketch and attic square footage. Tell us the intake and exhaust vent products you want to use — or we'll recommend some — and tell us about any additional constraints. An estimate will follow.
We calculate and draft
Net free ventilating area (NFVA) is calculated and the ventilation drawing is drafted against your specific roof.
Review and revise
You will have an opportunity to review and offer any comments before we send out final drawings. Review copies are watermarked "preliminary — not for permitting"; the clean, submittal-ready set follows once you approve.
Submit for permit
Delivered as a permit-ready PDF: a sheet of compliant attic ventilation calculations plus a professionally drafted attic drawing showing vent locations, sized and labeled for direct inclusion in the submittal set. If your jurisdiction requires a stamp, the package can be folded into your architectural set as consultant drawings, to be reviewed and stamped by the architect or professional engineer of record.
Who we serve
- Production home builders
- General & custom builders
- Architects & designers
- HVAC contractors
- Homeowners & remodelers
Types of work
New construction
Ventilation calculations and drawings for a single home or an entire plan library, including plans with multiple roof options.
Existing homes
Diagnostic packages for older homes, where an HVAC replacement or remodel turns up an attic that no longer meets current ventilation levels. It's the same R806.2 math either way: a calculation and drawing that gives you a code-benchmarked target to build to.
About PermitVent
PermitVent is run by Daniel Rodriguez, who has spent the last 12 years producing attic ventilation calculations and drawings for production home builders in Texas, along with residential plan libraries, construction documents, and as-built drawings. Daniel holds an Industrial Engineering degree from Texas A&M University, an MBA, and a Six Sigma Black Belt, and brings a process-driven approach from his early career designing production facilities and optimizing manufacturing systems.
Have a set of plans that needs a ventilation package?
Send us your scaled plans so we can get started right away. Most packages turn around in a few business days.