Skanska’s Rune Stene, the head of the Powerhouse collaboration that produces industry-leading ‘energy positive’ and Paris Agreement-aligned buildings, shares his perspectives on how the drive to cut energy use and carbon emissions is changing buildings and how those structures are produced.
Rune Stene is redefining the relationship between buildings and energy. He’s the Managing Director of Powerhouse, a collaboration of companies – including Skanska – dedicated to making ‘energy positive’ and ‘Paris-proof’ buildings. These role model buildings produce more energy than they consume over a 60-year life cycle while aligning with the climate ambitions in the Paris Agreement.
Achieving this ambitious level of building performance results from fusing forward-thinking, highly efficient architecture and engineering with renewable energy sources, such as solar panels and geothermal energy. Energy use is closely correlated with carbon emissions, so with society concerned about our warming planet and the availability of natural resources, it’s increasingly important to produce buildings that require less energy and carbon. With Powerhouse buildings, carbon emissions from materials and the building process are reduced to a minimum, including through material re-use and upcycling.
Here, Rune, also the manager of Skanska’s Acusto interior construction business in Norway, shares his perspectives on how the drive to cut energy and carbon is changing buildings and how those structures are produced.
Becoming part of the solution
“Companies and organizations need to become part of the solution for climate change. Nearly every country has signed the Paris Agreement. But climate challenges can’t be solved by governments alone. Companies need to create and expand the markets to take solutions forward.
“The customer behind every building needs to find the right level of green for them and their project. For most, it is not about breaking new ground. The competencies are already there. The solutions are there. The materials are there. It is also not about building a lot of Powerhouses – there should only ever be a small number of those, as they should be the most ambitious energy and climate projects on the market. Choosing to do something, even if not the biggest or the best, makes you part of the solution.
“Maybe it is better to use a few more kilowatt-hours of electricity than use a lot of materials with huge carbon emissions.
“We still need to talk about energy and energy efficiency, but it’s carbon emissions that kill. So environmental targets need to be communicated around carbon. It is also about thinking differently. Maybe it is better to use a few more kilowatt-hours of electricity than use a lot of materials with huge carbon emissions,” says Rune Stene, Managing Director of Powerhouse.
Environmental ambitions driving design
”Form follows function’ is a traditional design expression. We have shifted that with Powerhouse, and made it ‘form follows environment.’ For example, with Powerhouse Brattørkaia, one of the world’s northernmost energy-positive office buildings, the high environmental and climate ambitions make it look different. The roof is sharply pitched at 19.7 degrees to provide the optimum angle for the photovoltaic panels to harvest the sun’s energy. And a big circular opening enables sunlight to reach interior offices. Form follows environment needs to be balanced with form follows function, of course. The building still needs to function well. But we want the customer and the designers to think in a different way by having the overall goal of being Paris Proof.
“We need to change our behaviors in our private lives, at work and with how we move about. I think most of us are ready for that to help in the fight against climate change. But how big are the changes we are willing to make? And how fast do we need to make them? That is what we need to consider.
Considering carbon during design and construction
“Retrofitting existing buildings offers huge potential to reduce energy and carbon emissions. We used best practices from Powerhouse Kjørbo, in which two roughly 30-year-old office buildings were transformed into energy-positive buildings, to help Harvard University with their HouseZero project. HouseZero involved renovating a nearly 80-year-old home to use near zero energy for heating and cooling and to produce zero carbon emissions.
“Carbon has become another factor to manage during design and construction. The construction industry is skilled at managing quality, cost and schedule to deliver projects. Adding carbon to the equation makes the balancing act even more difficult. If we add some materials to increase quality, we might have to add some solar panels to compensate for the carbon and energy from producing those materials.
Rethinking building materials
“Materials are where the biggest changes will come in the next 5 to 10 years. The energy used to operate buildings has been reduced. For example, building facades and heating and ventilation systems have become quite sophisticated. Now we need to examine the energy and carbon in materials, and in the building process itself. Those are the next big opportunities across the building life cycle. I don’t think we will use different materials – I still see concrete, steel, wood, glass and so on being widely used. But it will be a race to produce versions that require less carbon.’
“Form follows environment’ is the philosophy behind Powerhouse Brattørkaia, one of the world’s northernmost energy-positive office buildings.
“Even the construction phase is on its way to become carbon neutral. There is a push in Norway to have construction sites with no carbon emissions, especially in Oslo where a lot of the air pollution was found to come from construction sites. Equipment and machinery will either be powered by electricity or fossil-free fuels. The government has set a target to start moving the industry toward fossil-free building sites.
Scaling up with reducing carbon
“The scale of carbon reduction needs to increase. The biggest gains will come from getting all projects to perform better on carbon, even if not on a Powerhouse level.’
“It is essential that all key team members are involved from the beginning of a Powerhouse project. That includes the customer and their tenants, the contractor, designers and consultants. No one can create a Powerhouse alone – we need each other. The target of creating a Powerhouse unites us all. This lesson of collaboration should be applied more broadly across the building industry.
“One of the biggest challenges with reducing carbon emissions is finding a reference point in the design, a baseline. It is easy to come up with a number and claim a carbon reduction, but often those deductions can’t be verified. This is one of the reasons it is difficult for public customers to set demands on carbon during the bid stage. They are trying to find their way around this challenge. Skanska is developing methods and tools to help them.’
“Powerhouse has developed a Paris-proof curve that illustrates the need of carbon reduction based on a 2010 reference. It plots carbon emissions per square meters over 60 years against a time horizon out to 2100, with the curve showing the limit to help keep global warming to 1.5 degrees C. This graph provides a precise way to guide the design of low-carbon buildings. The Paris curve, which Powerhouse applies on all new projects, has been developed in consultation with several external climate research organizations.
Preparing for the future
“Customers are demanding buildings that are better for the environment and the climate. Buildings that don’t perform at a certain level of energy consumption could struggle in the future to find tenants. It is about securing assets for the future.
“Along with reducing carbon emissions, we also need to prepare for the climate effects that will happen because of what is already set in motion. A research project I am involved with is looking at making buildings more resilient. A building might stand for 100 years or more, but the climate in 100 years won’t be the same as now. In Norway, there will most likely be more rain and heavier winds. That creates a dilemma: If you make a building more robust with more concrete and thicker walls that means more materials, and more carbon emissions. Having the right competencies is needed to balance these priorities and reduce risk for the customer, and society,” he said.