Around here there are jobs for which permits are always required, like
buildings more than 100 sq. ft, any building with plumbing, decks,
swimming pools, major renovations.
The shit can hit the fan down the road if major work is done without a
permit. There is a couple in our town who ran into problems after having
build a granny flat in their house. Somewhere along the line the owner
was in an accident and became disabled. He wanted to make some
renovations to make it more accessible but the town refused to issue a
building permit because the house was not in compliance with zoning
limits. The town eventually caved and rezoned the property to allow it
but it cost the owner a bundle.
Zoning bylaws are sometimes almost a joke because people with good
connections or enough money find ways to get around them. One of the
most common scams around here is for someone to buy a house of an nice
big piece of property. They get a building permit that is conditional
on the old house being torn down upon completion of the new one. They
move their parents into the old house and build the new one. Then they
whine that tearing town the old house will put an elderly couple of
their home. Invariably the town caves and allows them to sever the
property with the old house.