Reconstruction of the office building Budova B at Prague’s Brumlovka district, together with optimisation of technology operation, has reduced the building’s energy consumption by more than 50 %

The office building Budova B, which was built in 1999 in the central part of the Brumlovka multipurpose district by Passerinvest Group, a.s., underwent a full renovation a few years ago. The revitalisation of the building and other improvements in the area immediately around it were completed in 2020. Part of the reconstruction of the nine-storey building with a leasable area of 14,600 m2 and 1,250 m2 of commercial space included the complete renovation of the façade and the roofs. At the same time, all the technologies ensuring a high-quality indoor environment were upgraded. Thanks to these innovations, the building now meets the standards of the category B energy label, which guarantees economical and efficient operation. By measuring all energy consumption before and after the renovation it is now possible to calculate exactly how much savings have been achieved through this project. With the renovation and subsequent optimisation of technology operation, it has been possible to reduce the building’s electricity consumption by approximately 50 % (2018 vs 2023), and the carbon footprint of the electricity and heat consumption has been reduced by a massive 65 % compared to previously.

“We decided to renovate building Budova B for several reasons. However, one of the main reasons was the energy efficiency requirement, which the building no longer met. So, our aim was to carry out the comprehensive revitalisation of the building, which would first of all lead to a reduction in its energy consumption and less impact on the environment, and secondly also to an increase in comfort for the tenants in the building,” says Martin Unger, the technical director of Passerinvest Group, a.s. He also adds: “In 2018, i.e. before the renovation, the electricity consumption of building Budova B was approximately 3.6 MWh. In 2022, after the renovation, the building consumed around 1.7 MWh of electricity. Compared to the consumption in 2018 this is a reduction of more than half. I would dare to say that we have been more than successful in achieving our targets. This result only goes to show the sense of investing in innovation in office buildings. The renovation provides a substantially higher user experience for tenants, energy savings and therefore also financial savings. And in addition, it helps to meet ESG targets for both tenants and the owners of the building.”

The following table shows the electricity and heat consumption and CO2 production for the years before and after the renovation of Budova B:

Following the successful renovation, in 2022 Passerinvest then focused on further optimising the operation of ventilation, heating and cooling technologies in order to achieve the maximum possible energy efficiency. So, in 2023, it was possible to reduce electricity and heat consumption, and with it also CO2 emissions, even more compared to the previous year. “Optimisation included modifications to the building’s measurement and regulation system, which, among other things, involved implementing an algorithm to control the HVAC units according to space occupancy and adjusting the central temperature according to the season. However, educating our tenants also made a significant difference, thanks to which we have been able to save additional energy costs,” adds Martin Unger.

The following table provides a comparison of electricity, heat and CO2 consumption for 2022 and 2023:

Optimising the operation of ventilation, heating and cooling technologies also included setting the algorithm for controlling the HVAC units according to occupancy, multiple resets of the manual settings of the room controllers and adjusting the central temperature according to the season. The result was a saving of 875 GJ, i.e. a 23.7 % reduction in heat consumption, when comparing 2022 and 2023.

Another interesting innovation that Passerinvest decided to make in building Budova B was the addition of a hygiene material press. An analysis of the mixed municipal waste in May 2023 showed a large proportion of paper hand towels, amounting to 13.4 m3 a month. By using a hygiene material press it was possible to reduce this volume by 17 containers with a volume of 1,100 l per month. What’s more, the pressed towels are taken back by the hygiene products manufacturer.

As part of the renovation work on the building’s façades and roofs, major changes were made to the building’s blue-green infrastructure. These measures included the planting of greenery on the building’s structures, and roof gardens and water features around the building, including a high-capacity rainwater catchment tank, were built to aid water retention.

Building Budova B technical parameters:
• Office building built in 1999, renovation completed in 2020
• 14,600 m² of office space
• 1,250 m² of commercial space
• Overall investment in the renovation of the building, including a new atrium and landscaping around the building – CZK 470 million
o HOF Awards 2021 – Best Renovated Building in Central and South-Eastern Europe
o Best of Realty 2021 – 3rd place in the Renovated Offices category

In this text Passerinvest replaces the company name Passerinvest Group, a.s.