According to conservative cleric Ayatollah Javadi Amoli, open kitchens don't allow homeowners to be protected from the eyes of their guests.
"Women should be allowed to do their work while they have guests without being watched by others," Amoli was quoted as saying in a meeting in the holy city of Qom, where he is based.
Every now and then, Iran's clerics and officials come up with new things they designate as "un-Islamic."
There are obvious un-Islamic items and behaviors, such as the consumption of alcohol, which is banned in Islam. But other things, such as open kitchens, may strike some as more odd, or at least out of touch.
Owning dogs is considered un-Islamic, even though some Iranians own them. Some people also wear tight or colorful clothes and makeup in public, all of which are officially no-no's. So are trendy hairstyles, but that doesn't stop some young men from sporting them.
Other actions and activities that have been deemed un-Islamic -- with varying degrees of correspondence to what actual people do -- include Western music, ties, the mingling of individuals of opposite sexes, women entering sports stadiums to watch soccer games, and advertising for banks.
The list is long.
In practice, the "un-Islamic" designation is often used to limit personal freedoms and to push state policies.
In the past two years, officials have also targeted social sciences for allegedly being un-Islamic. The campaign was said to be part of an ongoing state crackdown on universities, which had turned into centers of antigovernment protests.
Hard-line cleric Mebah Yazdi said last year that social sciences are not just un-Islamic, but they're against Islam. He argued that social-science graduates, who he said deal with matters such as freedom and human rights, cannot be expected to have a deep belief in Islamic principles.
The "un-Islamic" designation can also be used in political disputes.
After he was sacked last year, former Foreign Minister Manuchehr Mottaki accused President Mahmud Ahmadinejad of un-Islamic behavior.
"Sacking a minister while [he is] on a mission is un-Islamic, undiplomatic, offensive, and outside the practices of politics," Mottaki was quoted as saying.
Here are pictures of celebratory actions branded as un-Islamic in the Iranian hard-line media.
-- Golnaz Esfandiari