@Femi Ibrahim
Sorry you're going through this brother. However Here in New Jersey this would not be covered by a title search. Title searches typically cover liens and encumbrances against the seller and the property. Almost nothing at all to do with additions on a house unless they somehow affect title.
Here we have to obtain what's called a temporary certificate of occupancy if we're going to buy a house as is. Once applied for the city will do its research and tell us whether there are any open permits or any illegal additions to the house. Keep in mind that obtaining the temporary Co is generally the responsibility of the buyer in an as-is sale. Once you have a temporary certificate of occupancy, you can then close on purchase of the house. The temporary Co is also the municipality's way of saying that they are legally obligated Grant you permits in order to make sure the house conforms providing you givr them the proper paperwork when applying for the permits. In other words once you have a temporary Co in your hand with a list of the violations they found during the co inspection, you should have no problems getting permits to make everything right.
I've seen a couple of investors Crash and Burn behind skipping the CO process. In fact I just came across a property I have under contract where some investors purchased the vacant lot next door thinking they were purchasing the house I'm buying. Even went so far as to break into the property and started renovating before I guess they realize what happened. I figured they must have spent $85,000 on the house and put at least another $30,000 into the renovation before realizing they only purchased a lot worth no more than $10,000. However had theh gotten a certificate of occupancy from the city PRIOR to purchase, they would have known right off the bat that they were buying a vacant lot and not a single-family house.
Does your Town require that you obtain a certificate of occupancy prior to purchase?