Schematic designs, released today, bring Snøhetta’s addition to SFMOMA into clear focus: A snowy mountain that peers over the stolid darkness of the existing  Mario Botta building, glinting in the sun. The project’s craggy façade will be etched with terraces, stairways, and landings—an architectural reminder of the hilly terrain of San Francisco—as it looks onto a network of alleyways.

“We wanted to allow the intimate spaces to grow without and within the building,” said Craig Dykers, cofounder of Snøhetta, the internationally known firm that is making its West Coast debut with the $250 million project.

At 235,000 square feet, the addition is slightly larger than the existing building. While it can’t have the street presence of the original, it asserts its equality, if not its primacy, in a number of critical ways. Its massing study and exterior circulation plan were released earlier in the year, but the latest set of designs describe the interior program, the visitor flow through the building’s three entrances, as well as the façade treatment, a surface of etched concrete panels. Inside, there is a significant shift in the gravitational pull, as all the main visitor services will be relocated from the Botta into the Snøhetta addition. Visitors to the current Third street entrance will travel a wide staircase through the building to the main lobby on the other side, located on the second floor. The key change to the Botta interior is the removal of the central staircase under the building’s large oculus.  

“This is a complicated site, and I think the challenge has produced a better building. It has focused us on what is possible in terms of urban planning in the city, how we activate and energize these little streets.” said Neal Benezra, SFMOMA’s director.

Inside, the galleries will be “very direct,” said Dykers. “There will be no games about exposing structure; we’re keeping it tight and clean.” Within the white-walled galleries, warmth will come from wood floors and small gestures like the wood wrapping around the inside of gallery door frames. In addition to several outdoor terraces and viewing areas, Snohetta’s emphasis on landscape design can be seen in the 30-foot high living wall placed directly opposite the new entrance, which will act a visual magnet.

Construction is scheduled to start in the summer of 2013 and be completed by the start of 2016. During that time, the museum will close, collaborating with other institutions around the city to host a “SFMOMA Without Walls” program.