Multi-Tier Cultivation Units in Protected Ground: A Systematic Review of Construction Types, Resource Performance and the Normative Coverage Gap

Abstract

Purpose. Multi-tier (vertical) cultivation units are consolidating into an independent class of protected-ground engineering, yet research attention and normative regulation remain concentrated on the industrial end of the size spectrum. This review aims to systematise the construction types of multi-tier cultivation units, to consolidate their technological and resource- use indicators on a common scale, and to quantify - rather than merely assert - the gap in the normative framework that applies to small-volume units. Methods. A critical-analytical review was carried out on four source groups: international peer-reviewed literature, the engineering school of the CIS countries, national legal and building-code documents of Uzbekistan, and EN, ISO and ANSI/ASABE standards. Protected-ground facilities were classified by nine independent attributes expressed as a classification vector; four construction classes were compared across nine indicators; covering materials were compared by light transmittance, heat transfer coefficient and service life; and eleven normative documents were assessed against eight criteria on a three-level scale, with a coverage index computed for each criterion.