Building regulations for access to and use of buildings in dwellings and buildings other than dwellings and provides a baseline for accessibility in the built environment. Volume 1: The 2015 edition with 2016 amendments of 'Approved Document M: access to and use of buildings Volume 1: dwellings' only covers dwellings and contains updated guidance. In particular, it introduces 3 categories of dwellings: *category 1: visitable dwellings *category 2: accessible and adaptable dwellings *category 3: wheelchair user dwelling *categories 2 and 3 apply only where required by planning permission. The 2015 edition with 2016 amendments took effect on 1 March 2016 for use in England.