November 8, 2020

Carbon budgets to keep your building emissions in check and on track

60-70 per cent of a building's climate impact comes from the construction process and the rest from the use of a building throughout its lifetime. In a recently started project for the largest property owner in Sweden, Castellum, Ramboll will calculate and reduce the climate impact from construction of new buildings.

“It is really not more complicated than keeping a budget. With help from the building’s own carbon dioxide budget, we make sure to measure emissions of all parts of the project and to make conscious choices to keep the budget, just as we do with financial budgets," says Ulf Hedman,” Deputy Division Manager at Ramboll. Castellum's proven routines together with Ramboll's expertise will be used for the construction of a new office building in Gothenburg. Castellum's goal is to reduce the climate impact for all office projects starting between 2021 and 2023 by 15 percent compared to a conventional building. The long-term goal for Castellum is to be carbon neutral by 2030, which is more ambitious than the Paris agreement, stating that the world should be climate neutral by 2050. “There are currently no legal requirements to keep emissions at a certain level, but there is a requirement from the society. Why wait for a change in the law? If we can act now, we must do that, with the goal to become completely carbon neutral. We hope that Castellum's ambitious goals together with our knowledge and ambition in sustainable project planning will contribute to more work in the same direction," says Ulf Hedman. The measures with the biggest impact in the construction process are about material selection, optimized structures in order to reduce the amount of materials and recycling of materials. It is about taking care of resources wisely and not use more than we need. One example is floorplans lasting over time so that we do not have to consider future redevelopment. Then load-bearing walls can be placed more densely, beams can be thinner and thus require less material. Another example is to build with wood which is a lighter building material with less embedded carbon dioxide compared to concrete or steel. Through Ramboll's approach, the building's carbon footprint during its lifetime will be lower as the cost of construction will be. “These are the same types of trade-offs that are made in the fashion or food industry to reduce waste. It is about making our resources last longer and choosing materials that are good for the climate. We need to think new and innovative and free ourselves from traditions and what the industry has done in the past. By measuring continuously, we increase knowledge and awareness in all roles in the construction process, which is a prerequisite for a major change," concludes Ulf Hedman. The method can also be used for already renovation projects for example Ramboll will evaluate Castellum's project Koppartorget in Västerås.