Ulsholtveien 31 has solar panels, a green roof, and reduced parking—with nine spaces (two have electric charging stations) and an emphasis on bicycling and car-sharing. An onsite bicycle shop is added value for residents and neighbors alike. As for utilities, hot and cold water and electricity can be measured and tracked using an app. The solar panels on the roof of the rehabilitated building send surplus heating to charge nine underground wells for geothermal heating, and a shared geothermal heat pump is the main energy source for heating and water in both the old and new buildings. The original building also has a solar thermal collector on the roof and heat recycling of greywater.

The project solves a ventilation challenge in an environmentally friendly way, using what’s called the Lunos ventilation system. “Ninety percent of the heat is being recovered just by this,” Zohar says. “It’s quite interesting because we have no pipes. There are no air ducts.”

But before all of the bells and whistles were added, the team had to decide—what do eco-friendly apartments look like? How much should be invested and where? The rental project is aimed at young people saving money to buy their first apartments. In addition to making something affordable, the architects were tasked with creating a compact design to reduce the carbon footprint. “In Norway we live on 50 square meters (approximately 540 square feet) to a person,” Zohar says. “We can discuss environmentally friendly architecture as much as we want, but 50 square meters is not environmentally friendly. So there was a discussion with the municipality—how small can we build?”

The end result is apartments ranging from 300 to nearly 700 square feet, but they don’t feel too small with abundant natural light, large windows, great views, and skylights. Depending on the unit, you’ll find high ceilings and lofted areas, too. Zohar says the project will serve as an example for the future. “What we said for the competition is volume versus area. The smaller the apartment, the more volume it gets.”