Summary
Highlights
The speaker introduces One Angel Square, the new head office for the Co-operative Group, which consolidates twelve different businesses. The building, completed just before Christmas, is located near Victoria Station and is considered a new focal point for Manchester's evolving urban landscape. The initial brief for the building was concise, emphasizing the client's ambition and key drivers while allowing the architects freedom in solution.
A look back at Manchester in the early 1960s highlights the Co-operative Group's former head office, the CIS Tower, which was the tallest building in the UK at the time. This previous building, now Grade 2 listed, demonstrated the Co-op's visionary approach to commissioning buildings. The new building aims to re-establish the Co-op's presence as a top retailer and foster a collective spirit among its various departments, addressing issues where departments never met despite working for the same company.
The building's design addresses the evolution of the modern workplace, driven by technological advancements like smartphones, which have made being tied to a fixed desk obsolete. The goal was to bring everyone together under one roof, emphasizing a collective spirit through a central atrium. Early design options explored flexible, open-plan floor spaces and the ability to subdivide the building for future needs, ensuring longevity.
The design was influenced by the need for large floor plates (20,000 sq ft) with every desk within 7 meters of a window for natural light. This requirement led to a unique, bent form, creating continuous floor plates and a large central atrium. The 'Beehive' symbol, historically used by the Co-op, inspired the building's facade, aiming for a deeper resonance than just a motif, despite commercial drivers requiring flat glass instead of curved sections.
The building achieved exceptionally high BREEAM, EPC, and DEC ratings, making energy efficiency a core design driver. Features include deliberately low southern sections to maximize solar gain and daylight, 350,000 sq ft of exposed concrete for thermal mass, and a double-skinned facade that acts as a 'thermal duvet.' Natural ventilation is achieved without opening windows, using earth ducts to pre-cool air and a stack effect for air circulation.
The building's Combined Heat and Power (CHP) system is fueled by rapeseed oil grown on Co-op farms, demonstrating a closed-loop sustainable energy system. Excess energy can be fed back into the grid. The air system involves earth tubes that bring fresh air underground, leveraging the constant temperature of the earth for passive cooling before distributing it through a raised floor system via displacement ventilation.
The double-skinned facade features horizontal brise soleils that double as walkways for cleaning, designed to maximize daylight penetration while controlling solar gain. The vertical mullions of the curtain wall vary in depth based on orientation to block low angle sun, preventing overheating. Internal design focuses on visual connections, allowing occupants from any desk to see across the atrium to the city or surrounding countryside.
The building features unique tapering concrete columns that transition from blades in the car park to square profiles at upper levels, addressing structural needs. The project utilized Building Information Modeling (BIM) extensively, which prevented any clashes on site despite the geometric complexity, saving significant time and cost. The floor construction uses a hybrid steel-concrete system with precast coffers and in-situ concrete for optimal span and ceiling height.
Precast coffers, manufactured by Thorpe Concrete, were used for the floors. Steel molds were chosen for their durability, given the large number of identical components. The concrete soffits were painted white, not only to reduce lighting energy consumption by reflecting more light but also to appeal to the non-architectural occupants, transforming a raw, exposed concrete aesthetic into a brighter, more generally appealing finish.
The 'Outstanding' BREEAM rating imposed strict waste generation limits, requiring contractors to use bespoke, reusable packaging for materials. The building also incorporates 40,000 sq ft of expansion space, demonstrating a sustainable approach to future growth. Collaborating with Loughborough University, the building was designed to be resilient to predicted climate change over the next 50 years, ensuring its systems remain operational without significant modifications.
The exterior features a bronze anodized aluminum finish, known as 'Anna lock', chosen for its lifetime guarantee and low maintenance, despite a higher initial cost. This decision reflects the client's long-term vision and commitment to durability. The building offers amenities like cafe areas with flexible workspaces and terraces with city views, fostering a dynamic and connected environment for occupants.