The classification of a Listed building, is any building or structure built before the 1700’s, or between 1700 and 1840, that is in good condition or close to original condition and that has been listed as interesting either historically or architecturally.
There are newer listed buildings, but for anything built after 1940 the building has to be very important or unique for it to be put forward as a listed building and has to be at least 30 years old to even be considered for listing. Listed buildings are graded as to historical importance, grade I, grade II*, and grade II.
If you own, or are thinking of buying a listed building, it does not mean you will not get planning permission to alter, extend or improve it but you will need to apply for listed building consent from your local council, a decision will be made based on how your plans effect or change the site or buildings historical significance.
Grade I & II* listed buildings are considered to be of exceptional interest historically, architecturally & sometimes even internationally important, castles, bridges & forts etc come into these two categories but only add up to around 8% of all listed buildings. The other 98% of listed buildings come under grade II, therefore most homes that are recognised as being listed buildings are classed as Grade II, these are considered nationally important, but not on the same scale as castles or cathedrals.
There are more than 374,000 listed building entries in England.