Someone from the business world called and said industrial gross (IG) is a lease agreement where the landlord is responsible for real estate taxes and insurance, while the tenant is responsible for utilities, janitorial and items inside the building. On utilities in office buildings that have adopted this arrangement, sometimes the landord installs separate meters or he or she might charge a proportional share of charges incurred on meters for all or parts of the building.

This reference gives a mind-numbing array of leasing terms, and dances around IG. An East Bay reference spells out IG substantially as above.