The program alteration will be called non-intrusive, if it does not involve source text editing at all, i.e. it is reduced to extension of the set of program modules only. The subject of the article is to show that all evolutionary program alterations admit a non-intrusive implementation. To be precise, two statements are valid. (1) Each point of growth, i.e. hot spot of a program can be represented as a horizontal layer- an extensible set of homogeneous modules. (2) Each evolutionary program alteration can be represented in the form of a vertical layer- a set of modules intended for non-intrusive addition to one or several horizontal layers.