The multi-apartment project Hestur, Kista, Stockholm has been able to be built with a 36 percent lower climate footprint than comparable projects, according to research results from the Mistra Carbon Exit program. The lower emissions of carbon dioxide in connection with construction have mainly been achieved by using climate-improved prefabricated concrete, construction optimization and conscious product selection.
Ida Karlsson, researcher and PhD student within the Mistra Carbon Exit program, Chalmers University of Technology, has followed the construction project and made the calculations that show how big the differences have become compared to more traditional construction methods.
– Hestur is a clear example that it is possible to build with a lower climate footprint already today. The project group set common goals early in the project and shows that the focus on resource efficiency leads to big gains in both climate footprint and economy, says Ida Karlsson in a comment.
The project was carried out by the client ByggVesta, the contractor AF-gruppen and the framework supplier Consolis Strängbetong with the common ambition to develop more sustainable construction methods.
The housing project includes the construction of 220 rental properties and student housing in Kista, Stockholm. The innovative climate measures are part of ByggVesta’s and Consoli’s joint ambition to develop more sustainable construction methods.
– It is very gratifying that the study confirms the hypothesis that climate and cost efficiency go hand in hand. The development we are driving in the industry gives us the conditions to achieve a better and truly sustainable housing product with net zero emissions within 25 years. To reach the goal, continued focus, cooperation and increased demands on heavy industry, new smart material recipes, recycling, electrification, higher accuracy, renewed dimensioning requirements etc. are required. There is great potential going forward, says Marcus Svensson, CEO of ByggVesta Development
The prefabricated concrete elements consist of Green Spine Line and of climate-optimized concrete from Consolis Strängbetong, where the proportion of cement has been reduced and replaced with other binders.
Result calculation:
Hestur’s climate footprint is calculated at 207 kg CO2e/m2BTA. This is a reduction of 36 percent compared to comparable projects in prefabricated construction (comparison projects from a compilation made by KTH). The climate impact of the Hestur project is 8,400 kg CO2e per resident, which can be compared with the sector reference for concrete houses of approx. 18,000 kg CO2e per resident, a reduction of more than 50 percent compared to the sector reference for concrete houses.
For example, the hollow decks (which make up the floor and ceiling in a concrete frame) have been optimized and the thickness of the interior walls has been reduced in the apartments higher up in the building. These are measures that contribute to less material consumption and thereby a lower climate footprint, without affecting performance such as load capacity or noise class.
