To function properly, sustainability criteria should not be incorporated in a legal framework alone. They should be accompanied by other structural elements, which would answer for such important aspects as enforcement of the sustainability criteria, their supervision, administration, control of their fulfilment and reconsideration of the achieved results. With other words, a whole unit with sustainability criteria and elements needed for their implementation should become a part of a legal framework.   The number of accompanying structural elements, which together with sustainability criteria form the incorporated unit, can vary depending on a legal context, but some of the elements are indispensable: without them a legal framework will not function. In such a way, it is possible to differentiate between obligatory and supplementary accompanying structural elements. Obligatory accompanying elements are those that cannot be omitted without causing irreversible damage to the function of the legal framework. As an example of obligatory elements, mechanisms which answer for enforcement and control of the fulfilment of a regulation can be named. Supplementary accompanying elements are those, which facilitate the work of the obligatory accompanying elements and the whole legal framework. Still, there is no urgent need to include them in a binding legal act. They can be recommended in soft policy documents and freely chosen by those who implement the legislation.