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Queen’s Building, Emmanuel College

Cambridge, UK

By bringing deep technical rigour, a spirit of experimentation and a close collaboration with architect and craftspeople, º£½ÇÊÓƵ helped realise a building with an ambition that far exceeded its modest size.

Completed in 1995, the Queen’s Building at Emmanuel College, Cambridge stands as a quietly radical piece of engineering, one that re‑examined traditional construction through the lens of contemporary performance, research and precision.

Designed by Michael Hopkins and Partners and located beside the College’s 17th century Wren Chapel, the building accommodates a music recital room and lecture theatre, practice spaces and tutorial rooms. Its plan is compact and controlled, yet its impact has been significant, earning multiple awards and becoming a reference point for the modern use of loadbearing stone. For º£½ÇÊÓƵ, the project marked a move away from lightweight structures towards a heavier, materially expressive architecture, using stone not as cladding, but as structure, acoustic mass and environmental moderator.

The Queen’s Building is at once rooted in Cambridge’s architectural lineage and confidently contemporary. It is a building shaped as much by meticulous engineering research as by craftsmanship, where the integration of structure and building services solutions delivered an acoustic and environmental performance that was fundamental to its success.

We pioneered a research‑led approach to loadbearing stone, enabling a contemporary structure grounded in historic material and long‑term performance.

Our team worked hand in hand with architect and stonemason, translating traditional craftsmanship into precise, regulation‑compliant engineering.

Our experts integrated structure and building services to create one of Cambridge’s quietest performance spaces.

We delivered durability, acoustic excellence and clarity of construction through meticulous testing, detailing and collaboration.

Challenge

From the outset, the project set º£½ÇÊÓƵ an unusual and demanding brief. The College required an auditorium capable of supporting high quality musical performance and recording, with exceptionally low background noise levels. At the same time, the building needed to sit comfortably alongside one of Cambridge’s most sensitive historic settings, using the same honey-coloured Ketton limestone as the neighbouring chapel, but without resorting to pastiche.

The decision to construct the building’s perimeter as a solid loadbearing stone frame created both opportunity and complexity. Structural stone of this nature had rarely been attempted in modern buildings, and very little reliable data existed on the mechanical behaviour of Ketton Stone masonry. Building regulations and design guidance were not well calibrated for a three-storey stone frame built with extremely fine mortar joints and subjected to eccentric loading from floor slabs, roof structure and a cantilevered gallery.

The performance requirements of the auditorium intensified the challenge. To achieve recording-studio levels of acoustic isolation, the building required an unusually heavy envelope, including a massive roof and stone frame, while still accommodating daylight, ventilation and a gentle relationship with its surroundings. The roof, in particular, posed a critical challenge, as it needed to provide acoustic mass without becoming visually ponderous or structurally inefficient.

After isolating external noise through the use of mass in the stone structure and roof, the building services systems were required to provide a high level of environmental comfort and stable conditions for audiences, musicians, and their instruments. Air quality, temperature, and humidity needed to be carefully controlled, all while maintaining noise levels below typical hearing thresholds.

There were also significant procurement and construction risks. Ketton Stone represents only a tiny proportion of material quarried at source, and its quality varies depending on bedding, orientation and flaws. Without careful selection, testing and handling, the stone could fail structurally or weather poorly over time. Achieving millimetre-perfect tolerances in loadbearing masonry demanded an approach closer to cathedral building than contemporary construction, requiring sustained collaboration between engineers, stonemasons and contractors.

Solution

º£½ÇÊÓƵ’s response was to treat the stone frame not as a conventional engineering element, but as a subject for research, testing and continuous refinement. A comprehensive programme of investigation was undertaken, beginning with a desk study of Ketton Stone, including laboratory testing led by Emmanuel College Fellow Dr Chris Burgoyne, followed by further testing of small specimens, scaled columns and full-size mock-ups. This work established reliable structural properties for the stone and, crucially, demonstrated that traditional masonry techniques, when executed with exceptional care, delivered materially superior performance.

The resulting structure comprises 28 post-tensioned Ketton Stone columns arranged around a flat-oval plan. Each column contains a stainless steel post-tensioning rod, carefully threaded through the stone and stressed to ensure that the masonry remains in compression under all service conditions. The rods are expressed at adjustment points, making the structure legible and allowing for long-term inspection and maintenance. This approach enabled the stone columns to resist eccentric loads from the floors, roof and cantilevered gallery without cracking.

Flat stone arches link the columns at each level, forming continuous rings that contribute to the building’s stability, while a central reinforced concrete core provides lateral restraint at lower levels. Floor slabs and the gallery are integrated into the stone frame through precisely detailed kneeler blocks, ensuring clear load paths and controlled movement. Beneath the building, bored piles were used to minimise differential settlement, protecting the integrity of the stone structure.

Acoustic and environmental performance were treated as inseparable from the structure. The mass of the stone frame, exposed concrete floors and heavy composite roof and extensive used of exposed timber helps to stabilise internal temperatures and humidity, while also providing exceptional sound insulation.

Fresh air is supplied at low velocity via a parametrically optimised concrete plenum and then through grilles beneath the auditorium seating, with large ducts and remote plant deliberately sized to eliminate noise. Even the light fittings were bespoke, profiled and tested to avoid audible hum in recording conditions.

Throughout design and construction, º£½ÇÊÓƵ worked in particularly close partnership with the stonemason. Stone was selected at the quarry with careful attention to bedding and grain, and each unit was tracked from extraction to installation. Mortar mixes were refined through trial and testing, arriving at a modern interpretation of traditional lime-based bedding that achieved almost complete contact between stone units. The result was masonry built to tolerances of less than a millimetre, with joints as fine as two to four millimetres.

Value

The Queen’s Building demonstrates the value º£½ÇÊÓƵ brings in ensuring engineering is treated as a creative, research-led discipline rather than a purely technical service. Through rigorous analysis and testing, the team enabled the use of loadbearing stone in a way that was structurally efficient, environmentally robust and architecturally expressive, expanding what was considered possible in contemporary masonry construction.

For Emmanuel College, this approach delivered a building of exceptional longevity. Its stone structure is not simply durable, but designed to be maintained, inspected and adapted over time, ensuring that it will continue to perform for generations. The acoustic performance of the auditorium established it as one of the quietest spaces of its kind, allowing the College to support high quality musical performance and recording and reinforcing music as a central part of its identity.

The project also stands as a model of collaboration. By working closely with architect, client, contractor and craftspeople, º£½ÇÊÓƵ aligned engineering precision with artistic intent, ensuring that structural necessity became architectural virtue. The visible post-tensioning details, the expressed weight of the roof and the finely crafted stonework all contribute to a building that is honest about how it stands up and how it performs.

Three decades on, the Queen’s Building remains a small but significant landmark, respected for its engineering intelligence. It is a reminder that innovation is not always about new materials or technologies, but about applying deep understanding, curiosity and care to materials that have been used for centuries.