Jay Honeck wrote:


It's not just me doing it -- it's our FBO. And a dozen or more
aircraft owners on our field alone.

They would appear to be breaking the law, if you consider city code of
Iowa City "the law."

13-4-3: REFUELING AND DEFUELING AIRCRAFT:

The following general rules shall govern refueling, defueling, oil
service and sumping of aircraft and placing fuels in storage tanks or
dispensers:

A.Aircraft Not To Be Running Or In Enclosed Space: No aircraft shall be
refueled, defueled or oil serviced while aircraft engines are running,
when aircraft is being warmed by application of heat or when aircraft is
in a closed hangar or a congested or an enclosed space.

There's no mention of older building being excepted or grandfathered out
of the fire code, in this public list of the city ordinances:

http://66.113.195.234/IA/Iowa%20City/index.htm

Like I'm always telling my students, you could look it up.
(they get so tired of hearing that!)