For a long time, the UK’s second city has sat in the shadow of London, but in recent years a number of high-profile engineering projects have put the spotlight firmly on Birmingham. None have done so more so than the city’s new public library.
The new structure has all the hallmarks of a potential engineering icon.
The 39,000 square metre building has two main functions: to encourage people to visit and use the public collection and to house the vast archives of documents recording Birmingham’s history. These need very different building types, one open and light, the other closed and highly controlled.
Designed by Mecanoo architecten and engineered by Buro Happold, the building’s exterior elegantly resolves these challenges on a compact urban site, while internally a huge circular book wall of steel and timber lining the atrium delivers immediate impact on entry.
The site lies near a listed building with shallow foundations, adjacent to an underground railway tunnel. The extent and depth of the basement were developed to minimise any impact on the listed building or the tunnel.
The foundations are pad footings on the rock for smaller column loads and bored cast-in-place piles for larger loads. Pad footings were used wherever possible to reduce costs. Bored piles were employed because of their large capacity (to carry high building loads, and to reduce pile numbers) and to penetrate the sandstone bedrock with minimal disturbance to these neighbouring properties.
The massing and form of the building is articulated with dramatic cantilevers that protect the building entrance and defy the weight of the book collection.
The building’s structural layout was suited for construction in either steelwork or concrete. The contractor adopted a concrete solution, which had the benefits of smaller delivery loads to a congested site, and a shorter overall programme due to reduced following trades.
The two cores are located in the corners of the building to carry wind loads in a structurally efficient manner. Fire protection is inherent in the concrete structure.
Archive storage standards usually require four-hour fire protection, but the fire engineers developed a fire engineered solution so that a reduction to two-hour fire protection was possible. This resulted in smaller structural sections and reduced the costs of structural fire protection.
The façade solution is both elegantly beautiful and functionally ingenious. The main façade is wrapped in a pattern made of aluminium circles from the first to the eighth floors. This filigree is fixed through brackets to the façade behind, which is mostly glazed, but also opaque at archives and louvered at plant-rooms. The glazed part is subdivided according to the ventilation strategy. The mixed mode ventilation areas required the installation of controlled dampers and acoustic attenuators. The remaining façade is subdivided to meet thermal and solar requirements.
The building has been designed to be an exemplary low energy and sustainable building, minimising the impact on the external environment and requiring less than 50 per cent of the energy of the existing Central Library building.
The environmental and indoor climate strategy heavily influenced the building massing and form, in particular the size and shape of the atrium space, and responded to the design brief set by the Client to achieve an exemplar and innovative design with a BREEAM Excellent rating.
Contributing to an impressive 40 per cent reduction in carbon emissions, Buro Happold has integrated an energy centre into the building to provide low carbon heating, cooling and electricity. The energy centre is also connected to the district heating scheme, providing additional resilience to the building and to the network itself, contributing to the expansion of the low carbon district heating network in the area.
Simulation was employed extensively to optimise the design for maximum passive performance and minimal energy demand. Along with a high performing envelope, one of the key low energy design concepts was the incorporation of a mixed-mode ventilation strategy.
More advanced building simulation techniques were used extensively throughout the concept and schematic design stages to predict building performance, allowing informed decisions to be made at these critical early stages of the project and giving overall confidence in the design.
To enhance the ecological value of the site, the building has incorporated several species of plants as well as bird and bat boxes following a site survey by an ecologist. It even includes a fruit, vegetable and herb garden to help promote healthy and sustainable lifestyles within the community.
Since opening in 1974, the original Library of Birmingham has become the most visited public building in the city and the busiest public library in the country. With the new building, the Council’s aspiration for it to be the best library in the world and the busiest in Europe has a greater chance of being realised.