Energy-Efficient Statoil Headquarters boasts an energy class B rating in Norway

Global energy (read oil and gas) company <a href="http://www.statoil.com/en/Pages/default.aspx" target="_blank">Statoil</a>is housed within an energy-efficient headquarters in Fornebu, Norway. Designed by <a href="http://a-lab.no" target="_blank">A-Lab</a>, the <a href="http://inhabitat.com/statoilhydro-office-by-a-lab/" target="_blank">Statoil Headquarters</a> is composed of a series of 5 rectangular prefabricated volumes stacked on top of one another. The cantilevered design works to minimize the overall building footprint, while the high-performance facade minimizes energy use. The center of the volume features an arching glazed roof that creates a massive central atrium that functions as the heart of the building.

Back in 2009, A-Lab won a competition against 40 other entries to design <a href="http://inhabitat.com/statoilhydro-office-by-a-lab/" target="_blank">Statoil's new offices</a>. Located in a park-like setting in Fornebu, Bærum, Norway, the office is composed of five rectangular volumes stacked on top of each other.

Parts of the volumes cantilever out over the grounds, but largely make for a small building footprint, which maximizes the surrounding park space.

Each volume is 3 stories high, approximately 140 meters long and 23 meters wide and was largely prefabricated off-site as a way to reduce overall construction time.

At the center of the stacked volumes is a large airy, light-filled atrium topped with a glass ceiling that serves as the circulation center and meeting space.

The envelope is key to the building's overall energy efficiency and carefully balances energy loss against solar heat gain and daylighting.

The long ends are clad in powder coated aluminum that act as a rain screen, while the gable ends feature grey, solar shading glass from the bottom to the top of the volume.

Heat is provided via a remote centralised heat source and 85% of that heat is then recycled.

Overall the building achieves an energy class B rating and has a calculated energy use of 103 kWh/m2. <a href="http://a-lab.no/project/statoil/" target="_blank">A-Lab's Statoil offices</a> was recently the winner of the W<a href="http://www.worldarchitecturenews.com/index.php?fuseaction=wanappln.projectview&amp;upload_id=21210" target="_blank">AN 2012 Award for Best Office Building</a>.

Inside the building's central atrium and meeting space.

The offices have a total area of 117 000 m2 with a building footprint of only 65 500 m2.

The office’s interior is designed to facilitate flexible functions with rooms that can adapt from large meeting centers to multi-person offices.

Evolution of the building's design.

Section of Statoil offices.