This all depends on what municipality you property is in. Each Town, Village or City has their own rules on what permits are required. These rules vary drastically from Town to Town. For example, If you live in the Town of Oyster Bay, you do Not need a permit for a Shed less than 10x10. However if you live in the Town of Hempstead, Permits are required for all sheds. It is best to check with your municipality before building.
If you plan on selling your house you will need to have your C/O's in place. We recommend starting the process at least 6 months prior to listing your house. If you find out that you need C/O's immediately before the closing, you may have to close with money in escrow.
Getting a building permit is a long process full of red tape. Local building departments are known for making it a complicated mess of inspections, objections, omissions, fees, lost paperwork and aggravation.
When filing building permits, the building department will look at the whole property and not just the structure you are filing for. Therefore if your goal is to get a permit for a new deck, you may need to legalize the shed, fence & central AC as well. This is a common delay in getting permits.
In order for Certificates to be issued, inspections are required. In most cases these inspections are Building, Plumbing & Electrical. Generally the inspectors check for smoke and carbon monoxide detectors, railings, foundations, egress windows and other building elements.
If a building inspector or code enforcement officer should come to you house unannounced, you are not required to let them in. You may make an appointment to come back at a time that is more convenient for you.