Does the thought of getting permits for mundane jobs around the house make you groan?  That would make you perfectly normal.  Unfortunately, when you go to sell your home, you may be groaning even more. 

Depending on where you live, your city or county planning & zoning or public works department controls building permits.  This differs from a code inspection and occupancy permit (which can be required by your city/county and fire dept) upon transfer, which is an overall safety inspection.  A building permit is issued for specific repair and improvement jobs done to your home during your ownership.  They can be very large or very small, and typically include structural, electrical, plumbing and heating/air conditioning work, but also for fencing, solar panels, termite damage, some drywall installations, exterior drainage, even tie walls and playsets above a certain height.  Most of us understand and comply with the permit process for major renovation projects on kitchens, decks and room additions.  Some are questionable like minor remodeling projects.  And then there are those that don't make much sense - replacing the toilet seal or replacing a window with a smaller one.  Many folks think this is just another revenue producer for the government.  I believe that most of this is for our safety and protection, but can be conservation related (some plumbing regs) or for aesthetics (which way the fence faces).  The revenue certainly offsets the cost to the city/county, but I do not believe it makes them any money in the end after paying their staff and can even be a financial loss.  This process is mainly for the health and benefit of the resident population. 

So permits - Did You or Didn't You?  Upon selling your home, the Realtor will have you complete a seller's disclosure.  This is very detailed and (the STL version) includes a section addressing repairs to structural elements and "all significant additions, modifications, renovations and alterations to the property during your ownership"; and asking if required permits were obtained.  Many of us assume the contractor applied for any required permits.  Unfortunately, that does not always happen.  Time and money are two important commodities in business, and contractors like to save both, besides not having a regulator nitpicking their work, and wanting to give a competitive bid.  Some ask if you want one, or even require YOU to apply for it.  Read your agreement with them.  There are also many jobs that don't seem big enough to require one.  In fact, St Louis County, which does unincorporated areas and many municipalities that contract with them, posts a list of things that do NOT need a permit in addition to the list that does.  Seems like they are the same length!  See http://www.stlouisco.com/YourGovernment/PublicWorks/Permits/BuildingPermits.  

** A common misconception is that you do not need a permit if you don't "move the plumbing", which is not always the case.  
** Some appliance stores are charging for permits for dishwasher replacement.  St Louis County requires a master plumber for this job, and to submit a Certificate of Replacement in lieu of a permit, unless it is in a different location which does require a permit. 
** St Louis County allows a homeowner to do their own plumbing work that requires a permit if they can pass a test. 
** I have had two client cases where a city or fire department, being called by a seller applying for a code inspection after going under contract, realized that a recently finished basement or plumbing work was not permitted, and required some drywall to be removed to check things out.  This cost one owner $800 and the other $2500 to redo and patch.  This is rare but can happen. 

If you ask me, I would have to advise you to get the permits as needed.  If you decide not to, or have already completed work without, just answer the question honestly and say no, or I don't know.  Be aware that the public can call a city or county and ask for the permit history on your home.  If it is a common area not to get permits, most buyers do not consider this an impediment to buying, especially if you produce the paid receipts and lien waivers from professional contractors.  And the longer ago it was, the less likely to be an issue.