Permitted development. Majority of attic/loft spaces can be converted into extra rooms without planning permission - under permitted development:

extra space added to the property should not exceed 40 cubic meters on terraced houses and 50 cubic meters on detached and semi detached properties;

freehold top flat attic can only be converted within the existing space (dormer construction would require planning permission);

loft roof should not exceed the height of the existing front facing roof elevation;

materials used for finishing the dormer should match the appearance of the existing rear elevation

side facing windows should be obscure glazed and 1.7 meters above the finished floor;

no verandas, balconies are allowed - only so called juliet balconies;

roof extensions should be set back at least 20 cm away from eaves - this does not apply to hip to gable loft conversions;

loft conversions are not allowed under permitted development in conservation areas.