The Ukrainian window community proposes adjusting the thermal bridge indicators for windows, doors, and walls in nZEB buildings

The Ministry of Communities, Territories, and Infrastructure Development of Ukraine has drafted an Order on requirements for nearly zero-energy buildings (nZEB). The Ukrainian window community participated in the development of the Order and submitted expert proposals on the building envelope.

Key requirements for nZEB buildings:

• Energy efficiency class:
  - New construction: Class A,
  - Renovation: Class B.
• Corresponding indicators of primary non-renewable energy consumption.
• The share of energy produced from renewable energy sources (RES):
  - At least 53% for the first temperature zone,
  - At least 57% for the second temperature zone.

Other requirements serve as safeguards to achieve the main ones. The Ukrainian Association of Transparent Structures Manufacturers, together with nZEB.PRO, organized a discussion within the window community specifically on the thermal performance requirements of the building envelope: windows, doors, skylights, and glass facades.

The community proposed revising the linear heat transfer coefficient PSI (ψ) by increasing it in the areas of thermal bridges at the joints of transparent and opaque building components. PSI measures the additional heat flow through windows or doors at the edges where glass meets the frame. The lower this value, the more effective the thermal insulation of the window or door.

The proposals have been officially submitted to the ministry.

Participants in the discussion included aluplast GmbH, Aluprof S.A., EVB, Framex, GEALAN, REHAU, Reynaers Aluminium, Schuco International KG, VEKA, VSThermo, WDS, Winkhaus, Wurth-Ukraine, Vikna-Star, and others.