Your current house rules may state something similar relating to hanging of radio or TV aerials from windows or making use of the fire escapes for purposes of placing objects:
Windows.
No radio or television aerial shall be attached to or hung from the exterior of the building. The building is wired for both a TV antenna (located on the roof) and cable TV, which can be hooked up inside each apartment at the Shareholder's expense.

Public Areas.
9. No article should be placed in the halls, on the stairway landings or fire escapes.

The legality of denying permission to residents who wish to install such devices including TV dishes may be founded in the following documents that are available through the Internet. They will help you understand the Board’s rights to decline such requests:
http://www.fcc.gov/cgb/cosumerfacts/consumerdish.html
http://www.fcc.gov/mb/facts/otard.html