top of page

Moisture can have a detrimental effect on your manufactured home. 

Did you know HUD has guidelines for the minimum amount of ventilation that should be part of the underpinning of your home? 

This easy calculator will do the math for you!

Vented Sheets:


Unvented Sheets:

Total Sheets:



Per the Model Manufactured Home Installation Standards published by HUD in 2003:


8.8.2 Ventilation Ventilation shall be provided for the crawl space with skirting as follows:

(1) At a minimum of 1 ft2 (0.1 m2) of free area for every 150 ft2 (14m2) of the home's floor area

(2) Except in arid regions with dry soil conditions, the following shall be permitted:

     (a) A uniform 6-mil (0.15 mm) polyethylene sheet material or other acceptable vapor barrioer material shall be permitted to be installed on the ground surface beneath the home to further reduce moisture.

     (b) Where an acceptable ground vapor barrier is installed and one such ventillation opening is within 3 ft (914.4 mm) of each corner of the home, the total area of ventilation openings shall be permitted to be reduced to 1 ft2 (0.1 m2) for every 1500 ft2 (140 m2) of the home's floor area. Ventilation openings shall be placed at or near each corner of the home and as high as practicable. Openings shall be located on at least two opposite sides to provide cross-ventilation.

2003 Model Installation Standards

bottom of page