Legal relations concerning spontaneous construction are a special construction, which is not a classic example of civil relations, which are characterized by legal equality, free will, property independence of their participants, which are collectively considered the fundamental foundations of civil law. The study identifies and reveals the components of the basis for the acquisition of ownership of unauthorized construction, including: ownership can be recognized as a person for the property, which must have certain characteristics, necessary and integral features (characteristics); such property, by its legal nature, must belong to immovable property; construction must be under construction or already built; illegality (illegality) of such construction; constructed real estate or property that is under construction is located on a land plot that has not been allocated for this purpose, property is built or is being built with significant violations of applicable building codes and regulations, etc. Provisions on the understanding of each of the components of the basis for the acquisition of ownership of unauthorized construction are disclosed. Peculiarities of application of norms on unauthorized construction depending on the will of the owner of the land plot on which the unauthorized construction was carried out are stated, as well as attention is paid to the possibility of acquiring ownership of unauthorized construction by a person who did not carry out construction or the land owner. Opinions were expressed regarding the referral of the issue of acquiring the right of ownership for unauthorized construction to judicial jurisdiction.