Buildings have been built in nearly the same way for decades, but as society faces urgent challenges related to climate change—consider the IPCC’s latest report—the status quo isn’t good enough.
The fact is, buildings account for 30% of global energy consumption and 28% of CO2 emissions. These numbers can be reduced dramatically with greater energy efficiency in buildings.
With the launch of Rockzero—initially in Denmark but with other countries to follow—the Rockwool Group introduces a modular stone wool wall system that is part of the solution to climate change.
Made from recycled and natural materials, Rockzero is strong and flexible, both in the design and construction phases, and achieves the highest levels of energy efficiency while still providing comfort to the people inside.
Strong, light and highly energy efficient
“With the development of Rockzero we saw an opportunity to make a product that meets the most demanding sustainability needs of society and the customer in terms of fire safety, energy efficiency, aesthetics and comfort but then also improves upon the building process without requiring craftsmen to learn new building methods,” says Steen Lindby, Vice President, Group Operations & Technology, ROCKWOOL Group.
Rockzero is similar to other light frame constructions that use steel or wood for load bearing beams in the exterior wall; however, Rockzero uses high-density compressed stone wool columns in combination with stone wool insulation and a thin steel frame to achieve a light, strong and more energy efficient wall system compared to most homes.
For example, in a typical building, 10% of heat loss is due to thermal bridges—areas of the building with higher thermal conductivity that allow heat to escape. With the Rockzero wall system, the stone wool prevents this heat loss, enabling the building to meet the European Commission’s definition of a Nearly Zero Energy Building (NZEB).
“The energy performance of the wall is typically specified by the architects. When new elements are added during the design process it is often difficult to maintain the specified energy performance without increasing the insulation thickness,” says Brian Hurup-Felby, Technical Advisor, Energy and Indoor Climate at Danish Energy Management A/S.
“The advantage of Rockzero is that no matter the layout or the location in the house, even in corners and around windows, it’s easy to calculate energy performance and maintain the thin construction.”
Tried and tested innovation
Many Rockzero homes are already built and occupied, including ten single-family homes in different locations around Denmark, built by HusCompagniet, Denmark’s largest turnkey building company, as well as a 1.5 story social housing complex in the town of Trekroner, built by Roskilde Municipality and a large Danish social housing organisation, KAB.
“We work with builders and craftsmen to develop all of our products. With Rockzero I’m proud to say the feedback from the people working on the sites and the families living in Rockzero houses has been very positive,” says Steen Lindby.
New process, traditional building methods
The modularity of the Rockzero system allows architects to design the building as they wish, with no limitations on layouts and finishes. And since the materials are light, strong and standardised, construction is quick, and mistakes are less likely.
“With the Rockzero system, the electrician and the plumber can easily penetrate the stone wool spacer and fix cables without special tools for drilling. This saves a lot of time in the construction process,” says Phillip Holbek, Carpenter for multi-disciplinary Danish building contractor, Mernild Byg.
Once a design and layout has been decided and construction is ready to begin, ROCKWOOL delivers exactly what the builder needs to the site along with start-up assistance as well as advice and checks during installation. No more cutting insolation at the site or hurried modifications and no special tools or skills are required—Rockzero can be built with a power drill and a pair of capable hands.