To limit the probability that organic material will remain under buildings, which could harbour insects or vermin, or decompose and release gases, spores and other contaminants, which could lead to negative effects on the air quality of indoor spaces, which could lead to harm to persons.
To limit the probability that soil will have an inadequate bearing capacity, which could lead to the cracking of concrete or asphalt that is used as ground cover in unheated crawl spaces, which could lead to the infiltration of soil gas, which could lead to negative effects on the air quality of indoor spaces, which could lead to harm to persons.