New Tallest Passive Tower Performs on Budget
Passive House construction has reached new heights. At 289 feet, Bolueta, a 28-story residential high-rise in Bilbao, Spain, has become the world’s tallest building certified under the standard. Named for the district in which it is located, the $14.5 million, 171-unit development (including a nine-story companion to the high-rise) consists entirely of social housing.
“There are no excuses anymore,” says Germán Velázquez, a partner at Varquitectos, the project’s Pamplona-based architect. “It is possible to realize such a project in Bolueta, and it is just as possible to realize one almost anywhere out there.”
The Passive House standard mandates an airtight, highly insulated weather envelope with triple-glazed windows and heat-recovery ventilation. Bolueta’s heating demand of just 5.7 kWh/m2a represents an 80 percent reduction compared to a baseline building. To achieve this within budget, the architect relied on careful detailing of basic materials rather than proprietary assemblies. Airtightness, the main challenge, was monitored with a blower door test for each apartment during construction and a final test on completion.
Because Passive House energy standards discourage irregular building forms and extensive glazing, buildings attaining the standard risk coming off as banal. Bolueta bucks this trend with a dramatic black facade of gleaming, large-format, composite aluminum panels applied in vertical bands of inclined planes. The color refers to the city’s 250-year-old heritage of coal-based industrial activity. (The shorter building will be clad in a gray version of the material, in a nod to the steel produced in the area’s foundries.) The reflective, dynamic nature of the panels gives Bolueta “a significantly lighter effect,” says Velázquez, than its large, simple volume might otherwise have achieved.
The project is being developed by the Basque government’s public-housing company, Visesa. The owner’s goals are two-fold: to provide residents with maximum comfort for minimum energy costs, and to serve as an example for private-sector developers. Next door to Bolueta, Visesa continues to lead by example: another Passive House high-rise is now under construction.