26 Aug 22 | Global Design News

Adrian Smith + Gordon Gill Architecture’s Xian Tower is a sustainable high-rise development and an homage to Xian’s rich cultural history

Erected by Adrian Smith + Gordon Gill Architecture for Greenland Holdings Corporation, Xian Tower is a sustainable high-rise development that responds to today’s environmental requirements and is inspired by Xian Warriors, the world-renowned terracotta soldiers, and Xian’s great city wall built during the Qin Dynasty.

Xian Tower has recently been awarded a 2022 International Architecture Award by The Chicago Athenaeum: Museum of Architecture and Design and The European Centre for Architecture Art Design and Urban Studies.

Xian is one of the oldest cities in China and is one of the birthplaces of Chinese culture.

The building’s long rectilinear form has four primary components: mass, atrium, roof pavilion, and trellis, all of which borrow from the city’s cultural heritage to create a sense of permanence and impenetrability.

The language of the exterior wall is based on the armor worn by the Qin Dynasty warriors, creating a façade that is highly responsive to its environment.

The primary exterior materials are metal and terracotta, chosen to help connect the building to the history of Xian.

Metal panels represent the lamellar iron plates further relating to the traditional Chinese warrior’s armor.

The building envelope responds to environmental conditions with passive solar controls that create ideal natural lighting levels.

Instead of a traditional fully glazed curtain-wall system, a punched window expression changes in density and depth on each surface, depending on its orientation and exposure to the sun.

By tuning the façade to protect each side of the building dramatically reduces the building’s energy consumption, creating a synergy between the look of the building and how it performs.

Glazed terracotta tiles frame the windows and sunshades, giving further protection to the glass from the direct sun.

Two pavilions at the top of the podium unify the body of the building to the trellis, the main architectural feature of the building.

Its lamellar-like glass fins create a textured surface that defines the architecture of the tower.

The trellis also helps create shaded spaces around the building that highlight the entrance and the surrounding outdoor courtyards.

Shading elements on the exterior façade provide self-shading, reducing the incident annual solar radiation by 25%.

With the building’s window-to-wall ratio at an average of 60%, shading elements are designed to be the deepest on the east and west façades, maximizing protection and self-shading.

Conversely, those on the north façade are shallower to maximize diffused daylight.

The largest solid panel on this version is 1.5 meters wide. Additionally, high-performing glazing and insulated wall assemblies minimize heat transfer through the envelope, reducing the cooling and heating demand of the building.

Renewable energy technology, such as solar photovoltaics (PV) integrated into the building envelope, can provide 25% or more of the building’s electrical needs, further reducing the net-energy use of the building.

The total energy savings goal versus a baseline building is a 75% reduction. The mixed-use tower has 101 stories with office space occupying the first 75 floors and hotel on the upper floors.

The subtle taper of the tower and the changes to the core as elevators drop off allow an ideal floor plate for uses at their respective locations in the tower.

The office space is divided into eight elevator zones and utilizes two sky-lobbies that add efficiency to the core and provide faster travel for occupants.

The office elevator groups range from three to six elevators each. The two sky-lobby shuttles are in groups of six, with the hotel zone using three sky-lobby shuttles to deliver occupants to Level 78 where they board four local elevators to the hotel floors.

Mechanical and area of refuge floors are located per local requirements and are coordinated with the various zones of office elevators and MEP floors to increase overall efficiency.

The tower is in the core area of the Fengdong New City District, directly west of the city center and this axial relationship is an important part of the overall master plan.

The location of the tower is coordinated so that it has a direct axis with the historic bell tower at the center of the Wall City of Xian.

On the east-west direction, the tower functions as the primary focal point between itself, the retail mall, and the conference center.

The open space has been organized as a series of passages throughout the site, connecting the buildings and reemphasizing the axial importance of the tower, as well as its role as the anchor for the development.

Each building has its own dedicated entrance and identifiable address, with direct access to the site from all directions.