European Patent Office renovation uses Holcim’s sustainable building solutions

Standing close to Vienna’s iconic Belvedere Palace in the city’s historic center, the European Patent Office (EPO) building is undergoing a renovation to create one of Austria’s most iconic buildings – using Holcim’s sustainable building solutions from foundation to rooftop.

Stunning new office spaces will be characterized by transparency and openness, with use of glass providing bright, lively rooms and visual connections with the outside space. Yet the renovation of the 50-year-old building goes beyond aesthetics: it is designed to be one of the most sustainable buildings in Austria.

The project uses only ECOPact low-carbon concrete with ECOCycle® inside to reduce construction emissions and drive circular construction, while Elevate Isoguard™ insulation contributes to the building’s energy efficiency in use.

The Challenge 
 

Following a 2019 feasibility study, the EPO decided that its current Vienna building had reached the end of its operational lifespan. While the study recommended redeveloping the site with a new building, the EPO took the more sustainable approach of stripping the office back to its original concrete skeleton for a reconstruction based on the plans of ATP architekten ingenieure.

With 80% of Europe's building stock projected to still be in use by 2050, repairing and renovating buildings with green retrofit systems is one of key levers we can use to decarbonize the built environment and achieve the European Union’s net-zero targets.

Since the EPO building lies in Vienna’s third district – close to the Belvedere Palace, Salesian Monastery and the university Botanical Garden – the design of the renovated building needed to seamlessly blend in with the city’s rich architectural traditions.

The Solution 

One of the ways PORR is making the Vienna branch of EPO sustainable is through use of renewable energy and energy recycling. Solar collectors will generate more energy than the building consumes, with the surplus energy then fed into the electricity grid.

Heating is provided by 20 geothermal probes that feed a heat pump. Additional energy demand will be met by the large-scale photovoltaic system and storage batteries, and BREEAM ‘Outstanding’ certification is planned for the renovation.

To help achieve the project’s sustainability vision, Holcim created bespoke innovative and low-carbon ECOPact concrete mixes for PORR. These offer a minimum of 30% lower CO₂ emissions compared to standard concrete, with approximately 1,500 cubic meters used.

In addition, the ECOPact mix developed for the EPO renovation contains Holcim’s proprietary ECOCycle® circular technology. Using this we are able to recycle construction demolition materials – from cement and aggregates to concrete – into new building solutions.

For the building’s roof and arcades, PORR used Holcim Elevate’s Isoguard™ AK PIR insulation to boost the building’s energy efficiency in use, facilitating its heating and cooling. One of the most sustainable insulation products to produce, these boards offer the same thermal performance as thicker and/or heavier insulation materials. The roofing solution chosen enabled the installation of solar panels and heat pumps that meet the building’s power needs in full.

The Result 

With the renovation nearing completion, the embodied carbon of the ECOPact is expected to be 38% less than traditional concrete, while primary material use was reduced by 26% thanks to the use of ECOCycle® construction demolition materials in the mixes.

Since the renovated building is expected to produce more energy than it consumes to deliver heating, cooling, ventilation, lighting and hot water, it serves as a lighthouse example of a sustainable renovation with Holcim’s solutions inside.