Office Buildings on Antonijas Street Named Concrete Building of the Year 2025
The Latvian Concrete Association has named an office complex on Antonijas Street in Riga as Concrete Building of the Year 2025, praising its thoughtful use of concrete in both structure and facades. The buildings have achieved near-zero energy performance and LEED Platinum certification.
The Latvian Concrete Association (LBS) has awarded its Concrete Building of the Year 2025 title to an office complex at Antonijas iela 17 and 21 in Riga, where concrete serves as both the structural backbone and the facade finish.
The facades of both buildings are made of mass-tinted concrete sandwich panels — a rust-toned Terracotta shade for the building at Antonijas 17, and a dark grey Anthracite shade for Antonijas 21 — designed to match the character of the surrounding street.
Volume of construction
Both cast-in-place and precast reinforced concrete were widely used. The Antonijas 21 building used 2,308 m³ of ready-mix concrete and 1,337.7 m³ of precast reinforced concrete, while Antonijas 17 used 2,455 m³ of ready-mix concrete and 1,245 m³ of precast elements. The precast components include wall panels, columns, solid slabs and staircase elements. Together, the pigmented concrete facades cover almost 5,400 square metres.
Factory-made facade panels arrived on site with windows already installed, speeding up construction and reducing costs and disruption to nearby residents. Massive structural elements were cast using CEM III slag cement, which generates less heat during curing and lowers the risk of thermal cracking.
Functionality and sustainability
The buildings were designed without internal columns, relying on a central utility core that allows each floor to function either as a single open-plan office or be divided into several separate offices. Both buildings have reached near-zero energy consumption levels and received LEED Platinum, the highest international sustainability certification for buildings. A life-cycle assessment was carried out during design, and low-emission construction materials were used.
The project was developed by Vastint Latvia, designed by architect Pēteris Bajārs, built by main contractor CONSIUS, and supervised by BLV ADVISORY GROUP. LBS board chairman Rolands Cepurītis said the award recognises a comprehensive approach to concrete use, where it simultaneously serves as structure, architectural expression, and the foundation of a sustainable environment for users.
