There are several levels of zero-emission buildings. The ZEB laboratory in Trondheim is set at a level where emissions are calculated not only in the design phase when materials are selected, but also in the construction phase and when the building is in operation.
Veidekke’s project manager Trygve Karlsen describes the ZEB laboratory as a groundbreaking project. He also believes that it may help to change the way suppliers to construction projects think about emission requirements.
“We get questions from the suppliers about why we have made the choices we have made. I believe that just something as simple as requesting environmentally friendly solutions can create a change in how the industry relates to CO2 emissions,” he says.
Zero emission targets affect material selection
According to Operations and Safety Manager Rickard Tällberg in Veidekke who is responsible for procurement, you get different challenges when zero emission is the ultimate target than when you “only” have budget and quality objectives.
“Emissions from materials are measured all the way from when they are harvested from nature until the finished product is installed on the construction site. Both the qualities of the materials and the amount used are important. An example of how this has guided our decisions was when we had to choose insulation. It stood between glass wool and rock wool. In terms of price and function, these are quite similar, but glass wool has significantly lower greenhouse gas emissions, which is why we chose it,” he says.
As much wood and as little steel as possible
The use of wood in the main load-bearing structures of the building is one of the most important material choices. Here, too, they have worked creatively, among other things, to ensure the least possible use of steel, since this is one of the worst CO2 offenders. Among other things, this has led to the wooden columns in the building being oversized in order to reduce the use of steel brackets.
“An element that both we and the client are very proud of is the main staircase. It is specially designed to avoid all use of steel. The stair treads in solid wood rest on wooden beams stretched out from a core of solid wood, almost like the branches of a tree,” says Karlsen.
Important operating choices
Also, on the operational side, simple choices can make a big difference. Lighting is one of these choices. Glamox has supplied all lighting for the building, both outside and inside. In order to achieve the zero-emission target, it has been important to use LED lighting with low energy consumption. Furthermore, all the luminaires are equipped with DALI drivers so that they could be included in a lighting control system.
“Building owners SINTEF/NTNU had clear demands. We’ve therefore had a strong focus on finding solutions that use little energy. Lighting is an important part of this. The results would have been poorer with a different lighting solution,” says Karlsen.
Another example of how different choices affect CO2 emissions during the operational phase is the lifts used in the building.
“One of the lift types we considered uses more power than the one we chose when it is in standby. This had a lot to say for energy use and thus the CO2 accounts, since lifts stand still most of the time,” Tällberg adds.
Solar cells contribute both to emissions and reduction of CO2
The use of solar cells is a very important part of the CO2 calculations, because it is the only way the building can produce energy. In fact, the solar cells were installed so early that they could be used to produce electricity already during the construction phase. The project manager nevertheless describes the use of solar panels as challenging as it affects the CO2 accounts on both sides.
“Production of solar cells is very energy-intensive, so it will be very important for the CO2 calculation to get the maximum amount of energy out of the panels,” Karlsen explains.
Useful collaboration meetings
In the design phase, Veidekke has worked closely with representatives from the client in addition to the architectural firm Link, HVAC installer Bravida and electrical installer Vintervoll.
“We’ve had a working group that has met regularly face to face. We spent a lot of time getting to know each other in the beginning. This has made it easy to come up with ideas and suggestions and the group has been very useful because experience from all subject areas has been represented,” says Karlsen.