They’re lucky that whatever cell phone tower is carrying their signals still has power. Also, they’re lucky not everyone in their area is on their cell phone overwhelming the tower.
A lot of improvements (at least in the U.S.A.) don’t require permits in most places. For example, painting, most repairs, flooring, etc. don’t require building permits. Adding walls, electrical, plumbing, gas, another room, etc. all require building permits (in the U.S.A.) for safety, zoning, and tax reasons.
Isn’t that what chocolate cheese cake is?