When a developer or architect receives a quotation for windows or a facade, it is full of abbreviations: DBN, DSTU EN, classes 4, 9A, C5, RC2. This guide explains which standard covers what and how to read a supplier’s documents.
Two levels of requirements
In Ukraine requirements for glazed elements work on two levels:
Building codes (DBN) set what the building and its elements must achieve — for example, how much heat windows may lose.
Product standards (DSTU, including those identical to EN) set how a product is tested and classified and which characteristics the manufacturer must declare.
The designer takes the requirement from the DBN; the supplier proves the product meets it with documents under product standards.
DBN V.2.6-31:2021 — thermal insulation
DBN V.2.6-31:2021 (opens in a new tab) “Thermal insulation and energy efficiency of buildings” replaced the 2016 edition and has been in force since 1 September 2022. For glazed elements of residential and public buildings the minimum reduced thermal resistance is:
0.90 m²·K/W — temperature zone I;
0.70 m²·K/W — temperature zone II.
Rooflights require 0.80 and 0.70 m²·K/W, external doors 0.70 and 0.60 m²·K/W respectively. The temperature zone is taken from the map in the annex. The DBN also require a check of minimum inner surface temperature to avoid condensation, and the energy class of glazed elements is determined to DSTU 8902.
DSTU EN 14351-1:2020 — windows and external doors
DSTU EN 14351-1:2020 (opens in a new tab) is an identical adoption of the European product standard EN 14351-1:2006+A2:2016. It came into force on 1 February 2021, replacing several national standards for window and door units. It lists the characteristics a manufacturer declares and the methods used to prove them.
Key characteristics and classification standards:
Air permeability — EN 12207, classes 1–4 (4 is best; test pressure up to 600 Pa).
Watertightness — EN 12208, classes 1A to 9A (600 Pa) and E750, E900 and above for pressures over 600 Pa.
Wind resistance — EN 12210, classes 1–5 by pressure (class 5 — 2000 Pa) and A/B/C by deflection (C is the strictest, 1/300).
Thermal transmittance Uw — calculated to EN ISO 10077-1/-2 or tested. Declared values use the 1.23 × 1.48 m reference window.
Burglar resistance — EN 1627, classes RC1N–RC6.
Sound insulation, load capacity of safety devices, operating forces and more.
A notation like “4 / 9A / C5” means air permeability class 4, watertightness 9A, wind resistance class 5 with deflection category C.
EN 13830 — curtain walling
Curtain walls have their own product standard, EN 13830 “Curtain walling”. It sets requirements for air and water tightness, wind resistance, impact resistance, thermal insulation (Ucw to EN ISO 12631) and other characteristics of the facade kit.
Glass
Glass has its own standards: EN 673 for calculating Ug; standards for toughened and laminated safety glass; EN 13022 for structural glazing. Glazing unit documents should confirm the build-up, Ug and glass type of each pane.
Installation
Declared window performance is only achieved with correct installation. Design and installation principles for windows and doors are described in DSTU-N B V.2.6-146:2010, and the installation joint was long governed by DSTU B V.2.6-79:2009. Note: according to the national standards catalogue, DSTU B V.2.6-79:2009 ceased to be in force on 1 March 2025. Always check the current status of standards in an up-to-date register before design.
What to check in a supplier’s documents
A declaration of performance for the system with classes under EN 14351-1 or EN 13830.
Test reports from an accredited laboratory referenced by the declaration.
A Uw/Ucw calculation for your project’s units, not only for the reference window.
Glazing unit documents — build-up, Ug, glass type.
Installation and care instructions.
Short glossary
Rq,min — minimum permitted reduced thermal resistance under the DBN.
Uw / Ucw — thermal transmittance of a window / curtain wall.
Declaration of performance — the manufacturer’s document with declared product characteristics under a product standard.
IDT — marks an identical adoption of a European standard in Ukraine.
Temperature zone — the climatic zone from the DBN V.2.6-31 map.
RC class — burglar resistance class under EN 1627.
Summary
DBN answer “what does the building need”, product standards answer “what can the product do and how is it proven”. When comparing offers, look at declared classes and project-specific calculations, not just the series name.
System documents are in Documentation and on the system pages.