North-facing passive office buildings and other unexpected innovations
Brussels, 25.03.2010 - REEEP International Secretariat
A passive office building in Manchester, England with a glass facade - facing north! A post-war housing block in Frankfurt, where a Passivhaus renovation cut energy consumption from 290 kWh/m˛ per year down to less than 20 kWh/m˛. A building control system that takes the weather forecast for the next 24 hours and uses this to adjust windows, external shades and other systems to keep the interior comfortable, even on sweltering summer days. A hotel in Platja de Palma where the renovation didn’t just reduce energy consumption, but also cut the CO˛ footprint to nearly zero. These were just a few of the interesting highlights of the “Making energy efficiency in buildings happen” side event during EU Sustainable Energy Week on March 25th.
The event opened with a keynote introduction by the Hon. Fiona Hall, Liberal Democrat MEP from the UK, who framed the entire building energy efficiency issue in practical terms: builders on the ground need to know how to deliver high efficiency solutions. She also noted the progress of the revised Energy Performance in Buildings Directive, which should set the stage for a step-change in the energy efficiency of European buildings.
Dr. Berthold Kaufmann, Senior Scientist from the Passivhaus Institut in Darmstadt, the organisation that effectively spearheaded passive house technology, gave several examples of how a renovation using passive house components - thermal insulation for a tight building envelope, passive house standard windows, and a ventilation system with heat recovery - can yield efficiency increases of 85% and higher, as with the Tevesstraße project in Frankfurt mentioned above. He also pointed out that passive house technology isn’t just about heating. A similarly tight building envelope in a hotter climate can work to reduce the need for cooling.
Building on this, Professor Mahdavi from the Technical University of Vienna pointed out that even in temperate climates such as eastern Austria, the temperature increase in the next 30 years will lead to a massive increase in the need for cooling. He presented a pilot project in simulation-based building controls where a piece of software considers the available options, e.g whether windows and shades are open or closed, and simulates these options for the next 24 hours based on weather forecast, and then updates the device controls to achieve the most comfortable temperature.
In fact, most office buildings in Europe, even in a place like northern England, consume more energy for cooling than for heating, pointed out Adrian Joyce, Senior Adviser at the Architect’s Council of Europe. He presented examples such as the BDP architect’s office in Manchester, a tightly-insulated building where the north facade is essentially glass, and the south facade has limited windows in order to minimise cooling requirements. He also showed an example from Portugal, the Solar XXI building, which combines an insulated building shell with integrated solar PV and solar thermal systems, and passive cooling via an earth-cooled system.
Continuing with the experiences in energy efficiency in a warm climate, Tomeu Crespí Seguí from the Corsorci Platja de Palma outlined a pilot hotel renovation project from Mallorca. There, the Hotel Royal Cupido, a 179-room hotel originally built in the mid 1970’s, has been renovated to reduce overall environmental impact by 50% and to achieve an overall energy efficiency class of B or better, while using recycled and low-emission materials in the process. From this project, an appraisal tool is being developed to be used in other hotels in Platja de Palma, a community highly dependent on tourism with some 192 hotels within its limits.
The individual presentations can be downloaded here: