NFIP Proper Openings

Proper flood openings, also known as flood vents, are structural elements designed to allow floodwaters to flow freely through enclosures, preventing hydrostatic pressure that could otherwise damage or collapse foundation walls. These openings are a key feature in NFIP rating as they reduce flood risk and may qualify for premium discounts.

Find more details in Technical Bulletin 1.

Requirements

To meet NFIP standards for proper flood openings, the following conditions must be satisfied:

Placement:

A minimum of two openings must be positioned on at least two exterior walls.
For partially subgrade floors, two openings are required on a single exterior wall adjacent to the lowest grade.

Height:
The bottom of all openings must be no higher than one foot above the higher of:

The exterior adjacent grade.
The interior adjacent grade or floor below the opening.

Size:

The total net area of openings must equal or exceed one square inch per square foot of the enclosed area.

Eligible Foundation Types

Buildings with the following foundation types may qualify for the proper flood openings discount:

Elevated with enclosure on posts, piles, or piers.
Elevated with enclosure on solid foundation walls.
Crawlspaces (elevated or non-elevated subgrade).

Engineered Openings

As an alternative to standard flood openings, engineered openings are certified designs that meet NFIP requirements:

Certification must be provided by a licensed professional (e.g., engineer or architect) and include:
- The professional’s license details and signature with an official seal.
- Validation that the openings allow for automatic equalization of hydrostatic pressure.
- Information on tested flood characteristics, such as water rise and fall rates.
International Code Council (ICC) Certified Openings:
- Products evaluated by the ICC are acceptable if accompanied by documentation showing:
  - Number of openings installed.
  - Square footage covered.
  - Model number.

Documentation

Policyholders must ensure accurate and complete documentation, including:

Details about the number and placement of flood openings.
Certification for engineered openings where applicable.
Elevation Certificate (if required) to confirm compliance.

Proper flood openings are integral to NFIP compliance, helping reduce structural damage risks while providing potential premium savings

This page is a rough draft and will need more work before it's finalized.

This page contains details about NFIP New Business.
Find more in the How To Write section of the NFIP Flood Insurance Manual.