One Rincon Hill

Location

The complex is on a 1.3 acres (0.53 ha) parcel on the apex of the Rincon Hill neighborhood. The site is bounded by Harrison Street to the west, the Fremont Street exit ramp to the north, the approach to the Bay Bridge (Interstate 80) on the east, and the 1st Street entrance ramp to the south.

Developer and architect

Solomon, Cordwell, Buenz and Associates, a Chicago architectural firm, designed the complex. The developer of this complex is Urban West Associates, headed by Mike Kriozere. The developer's headquarters are in San Diego, although all its highrise projects over 14 stories are in the San Francisco Bay Area. The Rincon Hill complex is the developer's second project in San Francisco, with the first being ONE Embarcadero South, a residential complex near One Rincon Hill and across from AT&T Park. According to the developer the total cost of the Rincon Hill project was US$290 million, rising to over US$310 million in 2009.

Architecture

The complex consists of two buildings joined together at the base by a row of townhomes. The South Tower and North Tower rise 641 ft (195 m) and 541 ft (165 m) above the corner of Fremont and Harrison streets, respectively. The North Tower has 50 floors, while the South Tower has 60. Because of the sloped Rincon Hill site, the South Tower's lobby floor or the 1st Street entrance is on the sixth floor, and the first floor is five levels underground from the 1st Street entrance. It is also one of the tallest all-residential towers west of the Mississippi River. Its location near the apex of Rincon Hill, at an elevation of over 100 feet (30 m), gives it an apparent height of well over 700 feet (210 m), making it one of the biggest additions to the San Francisco skyline in over 30 years.

Both the north tower and the south tower of the Rincon Hill complex bear a resemblance to The Heritage at Millennium Park in Chicago, a building of a similar height to the south tower also designed by Solomon, Cordwell, Buenz and Associates. The architectural style for both buildings of the Rincon Hill complex is late-modernist. The three sides of the South Tower facing southeast, northeast, and northwest have a linear glass curtainwall. The North Tower has a similar design, except it is shorter and the curved aluminum and glass side faces northeast. Both skyscrapers of the Rincon Hill project contain an oval-shaped crown housing mechanical equipment.

The crown of the South Tower contains a band of 25 LED floodlights that remain lit all night. Each LED light consumes little energy and has a lifetime of 40,000 hours. These lights are used to signal the weather, just like the lights on the John Hancock Tower in Boston. The crown glows red if warmer weather is in the forecast. A blue crown signifies that cold weather is expected soon. Green means that there is at least a 50 percent chance of rain. Amber indicates that the weather will remain unchanged. This is the San Francisco Bay Area's first weather beacon. The crown began lighting up on December 8, 2008.

Earthquake engineering

To support the 60 story condo tower, One Rincon Hill South Tower has a massive 4-metre (13 ft) thick pile-raft foundation embedded deep into serpentine rock. Although some engineers view serpentine rock with suspicion, there are massive structures, such as the Golden Gate Bridge, that have foundations on rock that is largely serpentine. Rising out of the foundation are the concrete core and large, tall columns of steel-reinforced concrete called outriggers. The core is attached to the outrigger columns by diagonal, steel buckling-restrained braces which are designed to dissipate energy during an earthquake through controlled hysteretic behavior. This type of advanced seismic system performs in a manner similar to that of shock absorbers. The braces are also encased in concrete and steel to further mitigate risk of buckling and strength loss. Also of note is the controlled-rocking system which features vertical post-tensioning which runs the height of the building through ducts within the reinforced-concrete shear-wall core. Many of these technologies used in the One Rincon Hill South Tower have never before been applied in the United States.

Water tanks

At the top of the building is a large tuned sloshing damper which holds up to 50,000 gallons (189,250 litres) of water and weighs 416,500 pounds (185,440 kg). A similar 50,000 gallon (189,250 liter) tank is located in the basement for firefighting purposes. There are two liquid damper screens in each tank to control the flow of the water to counter the sway from the powerful Pacific winds, which can reach hurricane-force.

Elevators

The South Tower has one freight and three passenger elevators. The elevators are the second fastest in the city of San Francisco, second only to those in 555 California Street and tied with those in 555 Mission Street. The elevators of the South Tower can travel from the ground floor to the 61st floor (the mechanical level) in only 26 seconds to speed passenger traffic flow. This means the elevators can travel about 1,200 vertical feet (366 m) in a minute. The elevators have artificial intelligence control systems that figure out passenger traffic patterns and dispatch the three elevators to handle passenger needs accordingly. The bottom of each elevator shaft has a cylinder filled with hydraulic oil to stop a falling elevator without injuring the passengers inside.

Residences

The entire project will provide 695 condos in the highrises and 14 townhomes at the foot of the towers for a total of 709 units. 376 of those condo units are located in the South Tower and the North Tower contains the other 319 units. Because of their height, both towers will offer spectacular vistas of the surrounding landscapes. There are 26 different floor plans for the 695 condos which are financially beyond the reach of many citizens residing in San Francisco. The units vary greatly in price from US$500,000 to US$2.5 million depending on view and the size of the unit that range from 600 to 2,000 sq ft (56 to 186 m²). The project opened up a sales office on June 16, 2006 and even before the opening, condo-buyers placed deposits for 130 of the South Tower's 376 condo units in a selling spree. The Sales Center is rumored to have cost US$2 million to build. The condo units in One Rincon Hill South Tower sold well for an unfinished building at that time. The first residents began moving into the South Tower in February 2008.

Prelude

The 183 ft (56 m) triangle-section clock tower, owned by Union 76 and then Bank of America, was built on the site circa 1955. After the Transbay Plan the city changed the zoning in the Rincon Hill neighborhood and raised height limits. A second version of One Rincon Hill was proposed in response to these zoning changes, in which the height was increased to 60 stories. The second version project was approved by the city on August 4, 2005. Before construction of One Rincon Hill, the clock tower was razed to make way for the construction of the towers.

South Tower

Three months after San Francisco approved the project, construction began on the South Tower with a groundbreaking ceremony on November 10, 2005. The South Tower was the second-tallest tower under construction in San Francisco.

July 2006 construction accident

On July 21, 2006, a metal construction deck collapsed sometime around 10:45 AM (UTC−7). Two carpenters and two ironworkers were injured when they fell about 30 feet ( 2.5 stories ) feet (6 m) along with the deck, sending all four men to the hospital. Three of the men were released that afternoon; one of the ironworkers was kept at the hospital with his leg broken in two places, a broken ankle, and a broken shoulder.

Progress

The South Tower was completed in September 2008, with all residential floors ready for residents. As of, April 2009, 70% of the South Tower's 376 luxury units and 14 townhouses had been sold. Because of the occupancy rate and low profits so far, the developers had initially refused to pay $5.4 million in development fees that would be spent on rent subsidies, job training programs and community development in the South of Market area. However, the developers finally agreed to pay the city.

North Tower

The remaining north tower was scheduled to begin construction after summer 2008 and be completed in 2009. Originally, construction was supposed to commence in January 2008. Later, the developer mentioned construction was going start in March, but the construction firm wasn't selected at that time. After March, the developer said construction was going to start in May 2008. However, following the worldwide financial crisis of the late summer and fall of 2008, the project's developers announced that construction of the second tower was indefinitely on hold. With improving economic conditions in the city, construction started on this tower on October 2012; its first residents moved in August 2014. The north tower was later renamed The Harrison.

Criticism

With condo prices set from US$500,000 to US$2,000,000, many critics have noted that the One Rincon Hill complex is too expensive for most San Franciscans. With the total initial development cost of US$290 million, the average development cost per unit with 709 units total is approximately US$409,000. However, the developer Urban West Associates has contributed a total of US$38.5 million to funds like the South of Market Community Stabilization Fund in order to address this concern.