The multi-purpose curved gable roof of the Pinch serves as an pedestrian ramp between the village's main elevation and a newly developed plaza.
Ema Peter The multi-purpose curved gable roof of the Pinch serves as an pedestrian ramp between the village's main elevation and a newly developed plaza.

In the village of Shuanghe, Yunnan, China, the curved gable roof topping the Pinch, a public library and community center, is a hybrid of forms and functions. The wood surface acts as a pedestrian ramp, playground, and seating for people-watching in the neighboring plaza below. It is also a symbol of the rural village’s rise over adversity.

In September 2012, a series of earthquakes struck the southwestern China province, killing more than 80 people and destroying thousands of buildings, including the school and nearly every residence in Shuanghe. As part of its recovery efforts, the government developed a plaza in the heart of the village. Olivier Ottevaere and John Lin, who are respectively an assistant and an associate professor of architecture at the University of Hong Kong (HKU), secured a grant from HKU to design and construct the 80-square-meter (861-square-foot) Pinch.

Located approximately 13 feet below than the village’s primary elevation, the plaza has a concrete retaining wall that Ottevaere and Lin repurpose as a bearing wall for the Pinch. The wall also lets the Pinch’s 123-square-meter (1,324-square-foot) roof become an accessible pedestrian bridge. The surface’s “gentle slope allows people to descend down into the plaza,” Ottevaere says.

View of the Pinch from the primary elevation of the village
Ema Peter View of the Pinch from the primary elevation of the village

The building’s roof, which echoes the shape of the nearby mountains, and three exterior walls are framed in timber as a nod to the traditional houses that once dotted the landscape, before the earthquakes. “We thought, ‘Instead of abandoning this material … why don’t we prove that we can use timber in a modern way?’ ” Ottevaere says.

The team specified birch that had been pressure-treated to resist the elements, fungus, and insect infestations. Trucks transported the wood approximately 250 miles north from Kunming Dianmuju Shangmao Co., a timber mill in Kunming, Yunnan’s capital, to the project site. Local construction crews hand drew the shapes of the Pinch’s 17 roof trusses on the plaza’s concrete floor. These templates were used to construct the trusses from 4.3-inches-wide-by-1.3-inches-thick boards, which are connected with 1-centimeter-diameter, stainless steel bolts. The trusses range in size from 4.9 feet wide by 9.8 feet tall to 19.6 feet square, and are spaced approximately 3 feet apart.

Exploded axonometric
Exploded axonometric

After assembling the trusses on the ground, the crews raised them upright by hand. One end of each truss bears on the concrete retaining wall, while the other rests on one of 17 timber columns. Steel brackets connect the trusses to the retaining wall and the columns, which anchor into the building’s concrete foundation.

The Pinch features 17 roof trusses, which bear on a concrete retaining wall and a timber column.
The Pinch features 17 roof trusses, which bear on a concrete retaining wall and a timber column.

Once the trusses were in place, crews nailed 64 3.3-foot-by-6.6-foot aluminum sheets over the trusses and injected silicone sealant in the lap seams. They then screwed 16.4-foot-long, 4.3-inch-by-1.3-inch wood decking, spaced 0.80 inch on center, over the aluminum panels. A 3.6-foot-tall railing traces the plaza-facing roof edge. The railing’s posts align with the columns below, while the rails match the roof decking.

A 3.6-foot-tall fence traces the edge of the roof on the plaza side.
Ema Peter A 3.6-foot-tall fence traces the edge of the roof on the plaza side.

The designers used the modeling software Rhinoceros and physical mock-ups to determine the roof’s three-dimensional geometry, which is created using the straight decking members. The modeling helped assess how much the roof decking could torque between trusses, Ottevaere says. The boards “are buckling in two directions: length and the width,” he says.

Twenty bands of 39-inch-wide polycarbonate corrugated sheets hang from the library’s exterior wood framing. Several sheets act as operable doors and open to the plaza.

Several of the polycarbonate sheets serve as doors that open up to the plaza.
Ema Peter Several of the polycarbonate sheets serve as doors that open up to the plaza.

Inside the building, the exposed wood structural system serves another essential purpose. Wood bookshelves hang from 13 of the 17 roof trusses, with space around them for circulation. Each bay contains three shelves, approximately 35 inches long and 8 inches deep, that hold approximately 200 books, for a total capacity of 2,400 books.

The roof trusses support 12 bays of wood bookshelves, each holding 200 books.
Ema Peter The roof trusses support 12 bays of wood bookshelves, each holding 200 books.

Fundraising for the project began in September 2012. The project was completed in April 2014 at a cost of 130,000 renminbi (approximately $20,000). Ottevaere says that the Shuanghe community and the children immediately embraced the Pinch. “Once they moved all of their books in, it was theirs,” he says. “[It’s] a monument to the earthquake and the rebuilding effort.”

The village has embraced the Pinch immediately following its opening.
Ema Peter The village has embraced the Pinch immediately following its opening.
Construction workers drew templates on the concrete plaza floor for use in construction.
Courtesy Olivier Ottevaere and John Lin Construction workers drew templates on the concrete plaza floor for use in construction.
Workers covered the trusses with aluminum sheets and filled lap seams with sealant.
Courtesy Olivier Ottevaere and John Lin Workers covered the trusses with aluminum sheets and filled lap seams with sealant.


The roof provides an ideal surface for people watching on the plaza below.
Courtesy Olivier Ottevaere and John Lin The roof provides an ideal surface for people watching on the plaza below.