Conservation areas are legally defined as areas of 'special architectural or historic interest, the character or appearance of which it is desirable to preserve or enhance'. The special character relates to the quality and interest of an area as a whole rather than just individual buildings. The Lake District Planning Authority web site has more information about conservation areas generally
Parts of Ambleside were designated a Conservation Area in 1980 and the boundaries were revised in August 2010. You can view a map of the new boundary here.
There was extensive discussion before the new boundaries were agreed and the Planning Authority produced a discussion document in June 2010, which contains a great deal of interesting material about Ambleside. You can download a copy here (3.7Mb PDF).
The committee has made its views known agreeing that extension of the Conservation Area was laudable but that any extension must be accompanied by much more determined efforts at enforcement. It also felt that the Board should not just “seek to ensure” compliance with its requirements but should be much more vigorous in pursuing compliance.