Malmö
The Challenge Sweden has always been on the forefront of developing buildings that achieve high levels of energy efficiency. Further advances are necessary, however, to meet the goals set forward by climate scientists. Among the biggest challenges in the building industry are continuing to increase efficiency gains while developing technologies that are both transferable and affordable.
The Strategy Having identified the goal to build energy efficient apartments at affordable rents, Stellar’s ByggVesta team recognizes these challenges as well as anyone in the building industry. Thus, when they purchased a plot of land in Malmö’s Western Harbor, they recognized an opportunity to push the envelope. As part of their building plan, the ByggVesta team identified one building to be a “passive house”. They decided they would set a goal of 65 kilowatt hours per square meter per year while using technology that could be easily transferred to other cities and countries. To do this, ByggVesta engaged architects, technology consultants, and entrepreneurs very early in the project conception stage, and managed the affordability of the units by sourcing throughout Europe to find the most affordable alternatives.
The Results Slated for construction finish in September of 2008, the “passive house” in Malmö has been calculated to meet the 65 kilowatt hour threshold. This calculates to 290 kilos (640 lbs) carbon dioxide per apartment each year, 65% lower than the average apartment unit in Sweden (485 kilos, or 1,069 lbs), and 265% lower than the average American residential usage (2,320 lbs) . More importantly, the technology is such that it can be transferred to other countries and areas. The key components to the project are thicker walls with higher insulation values, windows with low U-values, and a central heating system powered by a heat exchange system with a 90% recovery rate (ventilation exhaust and ventilation inflow system) located on the roof. To ensure that tenants are conscious of their energy usage, electrical and hot water usage is measured in each unit. Not satisfied with meeting the 65 kilowatt hour threshold, ByggVesta has set a 55 kilowatt hour per square meter goal for its new Stockholm project, Kajutan, which will be located in the Hammarby Sjöstad neighborhood.