Old office building in Sandvika transformed into the Tesla of the building industry

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1 Source: Aftenposten Innsikt, Sunday October 5, 2014 Old office building in Sandvika transformed into the Tesla of the building industry Buildings account for 40 percent of global CO 2 emissions. Suppose an ordinary, worn-out office building could produce twice as much energy as it consumes? This utopian idea is now a reality in Sandvika outside Oslo. Photo/graphics Per Kristian Bjørkeng Multimedia Per Byhring Three years ago, no one believed it would be possible to transform an ordinary office building into a real power station. But now, Powerhouse Kjørbo is ready in two of Saga Petroleum s old office blocks in Sandvika outside Oslo. Within the first few months after its opening, thousands of visitors from several countries have come to see the building. In addition to producing electricity, this is the first rehabilitated office building to be rated as «outstanding» for its design phase in the environmental classification system BREEAM-NOR. Energy accounts in the black The dark and seemingly boring building is not just turned into a passive house with extremely low energy consumption. It is in fact also energy positive, producing enough electricity to operate another building of the same size and standard. See the graphics on top of the page to learn more about the specific measures that have been implemented.

2 Through advanced energy calculations, it has been established that this building not only compensates for its own day-to-day operations, but also, through its useful life of 60 years, produces enough electricity to compensate for the energy used to set up and rehabilitate the building and produce the materials used. Buildings nearly three times worse than traffic There is always focus on the energy and carbon we use when we are driving. However, emissions from traffic are peanuts compared to ones produced by the building sector. While car traffic accounts for 15 percent of global emissions, the building sector accounts for 40 percent. If all buildings were to copy Powerhouse Kjørbo, this would nearly halve global emissions, and we would be much closer to a sustainable development. That is if the calculations are correct. If you had asked anyone in the Norwegian building and construction sector a couple of years ago whether it would be possible to achieve this in Norway, they would probably have told you no, says chartered engineer Olav Rådstoga, one of the employees at Powerhouse Kjørbo. He works with HVAC in Asplan Viak, and has also been part of the development. «If you had asked anyone in the Norwegian building and construction sector a couple of years ago whether it would be possible to achieve this in Norway, they would probably have told you no.» Established knowledge used from the start Despite the revolutionary results, there has been no need for new and revolutionary technology. But in contrast to a normal renovation project, where the architect draws a sketch and then brings in expertise from professionals as they are needed, all experts have taken part right from the start in this project with their ideas and requirements. All with the same target: How can a renovation project be completed in the greenest possible way? Everything has been designed to minimize consumption of energy and materials, both during building and operation. At the same time, the renovation has been made on a commercial basis. The special, cross-functional cooperation has resulted in a large number of measures (see the most important ones in the chart, and even more in the on-line version of this article), which in sum have provided considerable effects. The most important measure was to strip the building down to its concrete skeleton, and then to build it up by the book, extremely air tight, well insulated and energy efficient. Computers crave the most This work has reduced the building s energy needs by roughly 85% compared to the requirements of the prevailing Norwegian standard (TEK 10). According the standard, the requirement is a consumption of 150 kwh per square metre per year. In comparison, Powerhouse Kjørbo uses just 22 kwh a year. In addition, energy for heating and cooling is supplied from geothermic wells in the ground. The remaining

3 electricity needed is so limited that the roof, accommodating Norway s largest solar cell facility of 1550 square metres, produces twice as much electricity as the house needs for its own consumption. In fact, the building is so energy efficient that the operation and cooling of computers, which is difficult to avoid in modern buildings, require twice the electric energy that is needed to heat the rooms. The idea for this building came up at a conference arranged by the Zero Emission Resource Organisation in Powerhouse is a cooperation between several different companies in the construction and real estate industry, such as the aluminium profile company SAPA, Zero, the real estate company Entra, the construction group Skanska, the consulting company Asplan Viak, the aluminium company Hydro and the architectural firm Snøhetta. This group of companies has made the close, multidisciplinary cooperation possible. And it s allowed to open the windows! Architect Camilla Moneta has tried to ensure a high level of satisfaction among the users, so that they don t feel the need to renovate in the near future. PHOTO: Per Kristian Bjørkeng Like all the others in the team, architect and project manager Camilla Moneta in Snøhetta is brimming over with enthusiasm for the project s sensational results. She feels that working with environment and energy considerations as top priorities has given her profession a new dimension. Ever since the 1930s, the mantra of architects has been «form follows function». Now when buildings also get environmental and energy targets, this principle will be more precisely put as form follows environment. And with environment, we refer to the whole package both the energy ambition and creating surroundings that make people enjoy being here over time. We must still solve functional issues, appeal to sensualism

4 and create robust solutions. Good architecture is important; otherwise we will have demands for renovation after a few years. That is not sustainable, says Moneta. One example is that she has made it possible for the employees to open the windows, even though that is not an optimal energy solution. However, it increases the well-being of the users. Surprisingly efficient solar cell panels One of the most important measures in making Powerhouse Kjørbo an energy positive power station, is the intensive use of solar cells. They cover the entire roof. It turns out that solar cell panels are surprisingly efficient, also in Norway, as far north as in Sandvika. Here, the production of electricity from one panel is just 10 percent lower than in Germany, where solar cells have gained immense popularity. General manager Marius Holm in Zero believes these panels will gain considerable ground also in Norway. The solar irradiance in Norway is not as low as many think, it s just limited in winter. Solar cells fit very well together with hydroelectric power. It s there to take us through the dark winter months. In fact, the solar cells produce at their best when it s cold and sunny, and therefore they work optimally in late winter, Holm explains. No stimulation of solar power Locally, the office buildings are known as the old Saga Petroleum". PHOTO: Google Maps He points to the fact that there still is a lack of regulatory measures to stimulate the installation of solar cell panels in Norway. For example, you will be paid less than half of the price for the electricity you deliver to the grid as you will pay to get it back from the same grid. This means that the returns in the Powerhouse Kjørbo project could have been even higher than they are, if the market was more adapted. According to the consultant firm Asplan Viak, Norway is the only country in our proximity where there are no subsidies to stimulate power production through solar cells.

5 A great disadvantage related to solar cells, however, is that it takes a lot of energy to produce them, i.e. before they are installed. In fact, one third of all the so-called embodied energy in Powerhouse Kjørbo is related to the solar cells. Embodied energy means the energy which is related to the construction of the renovated building (the original «dirty» building process in the 80 is not included). That is why it will take two to three years of sunshine before the panels have paid back their investments and start giving a surplus in the energy accounts. Happy employees and a better reputation = win-win Will everyone now do the same as Entra, owner of Powerhouse Kjørbo, and payer of this expensive renovation? Managing director of Entra, Klaus-Anders Nysteen, says he is pleased to share his experience. He says that although the main target was to make an extremely energy efficient building, the work has also been carried out within a commercial framework. Since all materials used «cost» energy in the accounts, they have also achieved economic savings during the construction process. Klaus-Anders Nysteen, managing director of Entra FOTO: Entra For us, the cost was 5-10 percent higher than normal, although this is the very first Powerhouse to be built. The costs will be reduced in the next project. We have made many innovations in the first project, which of course will be used in the next projects, too. Our price per square metre is a little higher than normal, but most of the difference will be compensated for by means of lower energy expenses. In addition, the indoor climate is improved, the employees are happier, and the company s reputation is better. Thus, it s a win-win situation for the owner, the environment and the renter, he says.

6 Nysteen sees the building as a turning point for the entire building and real estate industry, since it has so many advantages that the entire sector now will turn in the same direction. Not for quick profits «You may call it the Tesla of the building industry.» «You may call it the Tesla of the building industry. At some point in time, the new, green technology will have come far enough to make people willing to pay for it, just because it is more competitive. I think we have passed that milestone now,» says Nysteen. However, not everyone can do the same as Entra, just like that. The government-owned company operates on a commercial basis, but develops properties which will be rented for many years. As such, the company may take a 60 year perspective of its property investments. That is not possible for a more expansive property development company, which may need to sell as soon as the building is completed. In such cases, it will not be very tempting to use expensive solutions that that will pay off in the long run for the building. Based on calculations and fortune-telling In addition, there is no doubt that the calculation which says that Kjørbo will earn back its building materials and be energy neutral after 60 years, is based on a number of assumptions which we cannot be sure of today. For example, the Powerhouse group needed to assume that the EU s political environmental targets will be reached during the next few decades. It is not given that this will happen. Henning Fjeldheim in Skanska has made many of the calculations. He admits that the energy positivity of the building is a kind of fortune-telling. Although I would prefer to call it a scenario, based on conservative assumptions about future political and technological developments. We have included continuous replacements of building parts based on empirical lifetimes. For example, all internal walls are replaced after 30 years, while we have assumed that interior surfaces will be painted five times during the lifetime of the building. All of this is in accordance with the average length of the rental contracts, he says. Tearing down the old building would have been more profitable Costs related to the construction of the old building are not included in the energy accounts. The concrete skeleton which was there before the renovation was therefore free for the project group. Still, it would not be possible to make a new building as energy positive as Powerhouse Kjørbo.

7 In theory, it would be more profitable to tear down the old building and start anew, if we were to judge by the energy accounts alone. But that would give no meaning in real life, says Fjeldheim. The next Powerhouse from the collaboration of companies will probably be a new building. This one will also be energy positive, although it will be located even further north. The project is called Powerhouse Brattørkaia, and is now pending approval from the politicians in Trondheim. About Powerhouse Powerhouse is a collaboration of companies in the construction sector. The target is to show that it is possible to build energy-positive buildings, even in cold Norway In 2050, the energy consumption in buildings might be equal to the total global energy consumption today, unless we change the way we build The EU has decided that all new buildings have to produce almost as much energy as they use by 2020 These buildings are called passive houses Energy positive buildings are even more efficient than passive houses, because they are net producers of electricity Powerhouse Kjørbo is one of Norway s first energy positive buildings Transforming an office building into a powerhouse Below you will find out how the Powerhouse cooperation has achieved what many thought to be impossible: WINDOWS Taller windows provide much light. Still, their size must be limited, as windows give poorer insulation than walls. They are not tinted, as the original windows, because sunlight should be used for heating. SUN SHADING The sun shading consists of exterior perforated blinds. This gives a more efficient reflection of the heat than when they are placed on the inside of the glass. GLASS PANELS OLD WINDOWS Making glass requires a lot of energy. Thus, the windows in the old facades were kept to reduce the environmental costs of the rehabilitation. The glass panels were placed in oak frames and used for indoor walls and office doors.

8 FACADE The facade is provided with further insulation on the outside of the foundation wall, going around one meter down into the ground. This prevents thermal bridges from the cold ground into the building. VENTILATION SYSTEM The ventilation system works at half the speed of normal systems. With that, the fans require just 1/8 of the energy needed for an ordinary system. The disadvantage is that the vents must be much larger, as the air flows more slowly. The advantage is that the users experience less draught and noise from the ventilation system, and that the staircase may be used as a ventilation shaft. GEOTHERMIC ENERGY Geothermic energy is provided by 10 wells going 200 metres down into the ground. As a consequence, no valuable solar cell electricity is being used for heating or cooling. ABSORBENT CONCRETE As much bare concrete as possible has been exposed to the users inside the building. Concrete absorbs excess heat during the day, and produces heat during the night. As such, it works as an energy measure in itself. However, this process will only be effective if the concrete is directly exposed in the building s surfaces. ACOUSTIC LAMELLAS Exposed concrete decks mean poor acoustics. In order to limit the negative effects of bare concrete, large acoustic lamellas and lamella baffles (lamellas in the ceiling) are installed to reduce sound. The lamellas are made of recycled plastic bottles. CARPETS There are carpets on the floors to improve acoustics. CONCRETE IN THE CEILING To expose as much concrete as possible in the ceiling, the traditional ceiling used in all office buildings has been avoided in the open zones and the offices. Instead, all technical installations have been gathered in core channels. LIGHTLING The light switches off in all rooms when there is nobody there. Sensors detect all movements and the light is automatically switched on when there is someone in the room. The fitted LED lamps use far less electricity than traditional light sources. RADIATORS On the external walls, there are no radiators, not even under the windows, as opposed to most other office buildings. This is possible because the house is extremely air tight and well-insulated. The heat loss from the external walls is so low that all heating can be made by means of a few, centrally placed radiators. They are hidden behind acoustic lamellas.

9 VENTILATION Fresh, cool air is pushed slowly onto the office floors. Here it heats up gradually, then rises naturally and goes out through valves from the offices and out into the staircase. Here, the now somewhat warmer air flows naturally up and out, with far less use of fans. TECHNICAL ROOMS Instead of placing technical rooms in the basement, the technical facilities are installed in a very limited space, making the ventilation ducts as short as possible. In this way, less material is needed for building. OPEN WINDOWS All offices have windows that may be opened manually. This is not very energy efficient, but is still important to increase well-being. JAPANESE FACADE To avoid energy demanding paint and to minimise maintenance, an old Japanese technique has been used to treat the wooden facade panels. The outer surface has been charred by flames, making it water-repellent and eliminating the need for paint. SOLAR CELLS Placed on the roof is Norway s largest solar cell installation. 155 square metres are enough to produce twice as much electricity as the building needs. COFFEE CUP RACK Everywhere, the quantity of materials has been minimised. Rather than using traditional, material demanding cupboards, Snøhetta has designed simple racks to keep the coffee cups in order.