Dandi Dan

For underground spaces, steady airflow is crucial — even a modest continuous fan with a fresh-air intake can make a big difference. Beyond ventilation, watch out for moisture buildup and make sure you have a good drainage plan. Those are usually the biggest issues people run into.

Even in mobile homes, radon can build up if there's enclosed skirting — adding better ventilation under the home or sealing and venting the ground area can really help long term