Suggestive of a strange and prehistoric fallen landform, the concrete structure is a ‘container’ to achieve the architect’s various visions, the outlook, the acoustic performance and how it echoes the natural surroundings should be crafted with creative solutions.  

Arup worked with OPEN Architecture to develop a purely integrated solution – the engineered structure without any decoration makes the hall with the perfect acoustic performance, with the service of structural and MEP engineering. 

Chapel of Sound is a new kind of regeneration project for China, which sits in a valley at the foot of Jinshanling Great Wall in Hebei Province. 

Developer Aranya approached OPEN Architecture with an initial brief for a concert hall that would act as the centrepiece to create a resort with generating work for villagers and revitalising the local economy. 

Unique geometry 


The structure is 12m tall and greatly over-stretches – with a small base of 12m x 14m and a top plate of 24m x 36m – offering a total GFA of 790m2. This unique shape creates large over-turning moment. To tackle this, tie walls were added at critical positions between inner and outer shells to make a spatial structural system. Our structural engineers also adopted topology optimisation to fine-tune the curvature of the concrete shell. 

Musician playing in the Chapel of Sound

Tie walls were added at critical positions between inner and outer shells to make a spatial structural system. 

Pleasure for the ear 

The semi-outdoor amphitheater and out-door stage posed great challenges to acoustic design. The steps and profile of the internal shell were set out through several iterations with the acoustic engineer to provide the best acoustic performance. The direct use of exposed concrete also eliminates the usage of additional decoration/acoustic materials. 

A comfortable amphitheater 

A computational fluid dynamic (CFD) analysis was carried out to evaluate the comfort level inside the structure as it is mostly dependent on natural ventilation. The openings at the roof and elevation were afterwards added or adjusted based on the results. 

Drawing of the chapel of sound design

The openings at the roof and elevation were added or adjusted based on the results applied by CFD analysis to evaluate the comfort level inside the structure. 

Cutting through the complexity 

Due to the complex geometry, all coordination of architecture and engineering was carried out in Rhinoceros software, from which we produced the structure and MEP drawings and 3D models for the contractor.  

We developed 3D set-out geometry and 2D layout drawings of all rebars (a total of 10,000!) to the contractor from the parametric model – which eased the contractor’s work a lot.  

The construction was the ultimate challenge – thousands of small pieces of timber plates, shaped differently, fit together like a jigsaw. Not to mention the 10,000 rebars, all different, were bended and fixed into the position. 

Sustainability 

The project was designed to create a local landmark with minimal material consumption. Exposed concrete forms all the space and satisfies all functions through digital design. Crushed local, mineral-rich rocks were used as aggregates in the concrete mix to create the special dark tone of the concrete surface, and the wood strips of the formwork were all  recycled.   

More than a tourist draw, the hall  will serve as a catalyst for the revatalisation of the area.