There are so many advances in technology that a lot of info your home is available to prospective buyers. One that is surfacing in many homes is the lack of proper permitting. I have had several big deals fall through because no-one got the correct permit when renovations were done. Buyers are paranoid (perhaps justifiably) that the local authorities or hydro will come do an inspection and have the wiring torn out or some other catastrophic result -
In comparison to your homes value, permits are extremely affordable. Permits give buyers comfort that correct inspections have taken place. between google earth and global information (GIS) systems made available to government agencies so that new deck or pool is visible and if they find it before you get a permit you might be paying double AND taking it down. Basement Developments generally need a permit and especially a hydro inspection this has been the scariest area of buyer resistance - and the news gets worse, disclosure when selling is practically mandatory so if you did work without a permit you must disclose it, then see how your buyer likes it. Alternately you may chose not to disclose - then if some problem turns up later - IE house burns down from faulty wiring installed without a permit. Their insurance company may decide you are liable and they could decide to seek compensation from you for not disclosing.
Those planning board people are very understanding if you talk to them first and the advice they are giving you comes out of the Canadian building code ( built largely on the unfortunate mistakes of others and common sense).
not all projects require a permit but it doesnt hurt to ask first and avoid "Almost sellers remorse"