On May 9, 2025, the prestigious Sustainable Construction Awards ceremony took place in Valladolid. ZEST Architecture proudly stood as a finalist with its innovative project, “Casa Tapial,” in the Single-Family Residential category, competing alongside five other leading projects from across the Iberian Peninsula.
Over the past nine editions, the Sustainable Construction Awards of Castilla y León have established themselves as a key benchmark for sustainable building and construction innovation in Spain. Organized by the Regional Government of Castilla y León and the Institute of Construction of Castilla y León (ICCL), this biennial competition highlights projects with a strong focus on sustainability in construction.
This 10th edition placed special emphasis on the European Union’s goals for climate neutrality and the standardization of sustainability criteria for economic activities within the EU, through the development of what is known as the European taxonomy regulation. The ultimate objective: moving from nearly zero-energy buildings to buildings with zero emissions.
ZEST Architecture’s three associate architects attended the awards event, held at the Assembly Hall of the Ministry for the Environment, Housing, and Territorial Planning of Castilla y León. During the ceremony, a short video presentation was shown for each of the finalists across the six award categories. The jury praised the outstanding work of all the finalist studios, selected from over 90 submissions received for this edition.
As part of the rigorous jury evaluation, all finalists were required to submit comprehensive documentation detailing their project’s energy consumption and carbon (CO₂) footprint, alongside a detailed presentation panel.
Our project, “Casa Tapial,” earned second prize in the single-family residential category. While it impressed with its strong architectural concept and sustainability, it also outperformed the first-place winner in measurable terms: an energy consumption of 61.90 kWh/m² per year and a remarkable negative CO₂ footprint of -15.004 kg CO₂/m² per year, compared to the first prize winner’s 119.70 kWh/m² and 3 kg CO₂/m² per year from Palencia, Castilla y León.
To read more about the winners of the 10th edition of the Castilla y León Sustainable Construction Awards 2023–2024, click here.
To learn more about our “Casa Tapial”, click here.
And if you’re curious to find out how a rammed earth wall is actually built, you can read our article here.