Summary
Six office buildings for the Inland Revenue of 1993 - 1995 by Michael Hopkins & Partners.
Reasons for Designation
The Office Buildings at the Inland Revenue Centre, of 1993-1995 by Michael Hopkins & Partners, are listed at Grade II for the following principal reasons:
Architectural interest:
* for the quality of the architectural design with an interesting mix of old and new idioms, demonstrating a new tempered modernism in the early-1990s;
* for the quality of the interior spaces;
* for the degree of survival, which demonstrates the sustainability of the original design and its flexibility.
Historic interest:
* as a major work of the 1990s by one of Britain's foremost contemporary architects;
* for the attention given to sustainability issues throughout the design;
* as an example of a large-scale development following a rare public design competition.
History
Nottingham in 1990 had relatively few office jobs, and house prices were among the lowest in England. The then government introduced a programme of moving public servants out of London, and the Inland Revenue announced its intention to create 2,000 administrative jobs in the city. It identified a site for new buildings on the western part of the goods yards, and the Percy Thomas Partnership produced a scheme to be realised by a 'design-and-build' contract. When Nottingham's planning committee questioned the scheme, the Inland Revenue brought in David Allford of YRM to make amendments. The footprint of the new scheme was given approval in 1991, but the City Council declared the design unsuitable for the location close to Nottingham Castle.
Following this, the government's first open competition for thirty years took place, conducted by the RIBA with Colin Stansfield Smith as head of an assessment team comprising two architects, Sir Philip Powell and Terry Farrell, along with James O'Hare, a representative of the Inland Revenue. By January 1992, of 134 applications, schemes by Arup Associates, Demetri Porphyrios, Michael Hopkins & Partners, the Richard Rogers Partnership and Evans & Shalev had been shortlisted. In late February, Michael Hopkins & Partners were declared the winners.
Within the long, rectangular site Hopkins arranged six main blocks on either side of a central road through the site, with secondary roads crossing between the blocks at right angles aligned to give views of Nottingham Castle. Roads were to be lined with trees and parking bays, and there was to be a central social centre with a tented roof, a feature that had become Hopkins's signature following the success of the practice's Schlumberger building in Cambridge (Grade II*) and the rebuilding of the Mound Stand at Lord's cricket ground. The office blocks could be built in phases, or some offered to other tenants should the Inland Revenue be reorganised. The Architects' Journal noted that the finalists all attempted to 'tame' their modernist credentials, either in their choice of materials or to meet the brief's demand for energy efficiency and naturally ventilated offices. Ove Arup & Partners were the structural and service engineers.
Work began on site in May 1993 but incorporated some foundations installed in April 1991 when the Percy Thomas scheme had won its outline approval. Moreover, a large amount of construction had begun off-site from February 1993. Speed of construction was important to make up the time lost by the abandonment of the first scheme and to reduce the costs incurred by the Inland Revenue, already renting offices for staff who had moved to Nottingham.
The design consciously reflected the style of the Victorian warehouses in the surrounding area, including those which the complex replaced. The lead partner for the development was William Taylor, born and raised locally, who understood Nottingham's architectural traditions. Taylor looked to carefully match the local red brick and found that the closest in colour and texture still being manufactured came from Barrow-in-Furness; the semi-engineering, low-porosity bricks were even of traditional imperial size.
The office blocks are formed around solid brick rectangular piers or columns with no reinforcement except a bar through the centre for lifting them into place, for they were prefabricated off-site in storey-high units. The sub-contractors Ryeton Builders used traditional mortar and an English bond save for the bottom bricks which were fixed to a plate by a special type of hard-setting liquid grout. These units were built into piers at 3.2m centres around the perimeter of the buildings and form the key feature of the façades. Each storey-high unit is capped with a precast concrete padstone, shaped to take the corners of two floor slabs. These prefabricated slabs, 14m long and 3.2m wide, around 300 in number and each weighing 24 tonnes (with 582 smaller units of various sizes), were lifted on to the piers and then grouted. They were cast in Stelmo steel moulds to give a very smooth finish, and each was shaped into a shallow arch which was left exposed on the underside to give a gently undulating ceiling that reflected natural light across the offices. It also had something of the look of a Victorian arched vault and was similarly chosen for its structural efficiency – arching the concrete increased its strength so the thickness of the slabs could be reduced. Electrical services were tucked into raised floors. The main contractors Trent Concrete also constructed the in-situ concrete service cores in the corners of the buildings, which also acted as wind bracing for the structure. The roof panels were finished in lead.
In April 1993 the scheme was awarded maximum points in a BREEAM environmental assessment, the first building to achieve this score. The Building Research Establishment Environmental Assessment Method had been established by the Department of the Environment in 1990 and was the first system anywhere for independently assessing the environmental impact of a building. At the Inland Revenue, the blocks’ narrow plans and opening windows encourage natural light and ventilation; there is no air conditioning. The steel windows are triple glazed for insulation. Nottingham’s innovative district heating system, based on a power station erected in 1973-4 at nearby Eastcroft to burn domestic waste, supplied the heat. Underfloor fans draw in air through vents in the bottom of the glazing where it circulates through the building; the corner staircase towers, clad in glass bricks to encourage solar gain, act as flues that draw warm air upwards, a process aided by vents that open or close according to the temperature. There is also a system of night-time cooling via the fans. The top floor, treated separately externally, is a large, open volume under an insulated roof with ventilating rooflights. Balconies and protruding slabs shade the building from direct sunlight, but there are also Venetian blinds in the outer cavity of the floor-to-ceiling triple glazing, with each bay having its own controls over these, as well as for the heating and lighting. There are opening windows, but the architects recognised that these would be used only as a last resort near the busy Wilford Road and the railway, so aimed to provide a comfortable temperature without them. They were sufficiently confident of the methodology that it adopted similar ventilation systems for Portcullis House, its parliamentary building in Westminster, commissioned in 1992 and largely designed in 1994 before the Inland Revenue was completed. It was used again at Nottingham University’s new Jubilee Campus, built in 1996-9.
The Inland Revenue Centre was completed in late-1994. In 1995 it won the Brick Award for the best commercial and industrial building of the year, followed in 1996 by a Concrete Society Certificate of Excellence and a 'highly commended' in awards for the Green Building of the Year, and in 1997 by a Civic Trust Energy Conservation Award.
Details
Six office buildings for the Inland Revenue of 1993 - 1995 by Michael Hopkins & Partners.
MATERIALS: the buildings are of brick, concrete and steel with sections of lead and glazed walling and lead roofs.
PLAN: the six buildings are laid out to either side of a central boulevard which runs roughly east-west through the Inland Revenue site. The two central blocks on the southern side are rhomboid in shape, with corner stair turrets and central courtyards. The remaining four blocks are L-shaped, with stair turrets on the external angles of the Ls, and internal turrets at each end.
The four buildings on the southern side are of three storeys. The two on the northern side, flanking the Amenity Centre, are of four storeys.
EXTERIOR: the buildings are all designed with the same palette of materials and architectural detailing throughout and so are not described here individually.
The buildings have structural brick piers which divide the window bays; these are wider at ground floor levels than first floor, with concrete blocks between the two. The piers narrow again to the second storeys where they exist. The concrete sections continue across the windows, where the arched form of the concrete floor structure is expressed externally. Windows themselves have brise soleil to their bottom halves and projecting glazed canopies above.
The uppermost storeys of each building project over the lower storeys and are clad in lead with smaller windows beneath the projecting roof structures with surrounding brise soleil.
The corner stair towers are circular on plan with glazed brick walls in steel framing. The uppermost sections have lead panels before a final row of windows, beneath the fabric 'caps' which raise and lower according to heat levels. Where the stair cores are contained within the ends of the L-shaped blocks, they are expressed externally with the lead panels and row of glazing with the same caps.
Each building has entrance points contained in bays adjacent to the stair turrets.
INTERIOR: the buildings comprise of open-plan offices on each floor arranged around service cores of lifts, toilet and kitchen facilities. The office floors were designed to be flexible spaces which could be used as fully open plan spaces, or which could be subdivided with moveable partitions.
At the lower floors the brick structural piers are expressed internally as are the concrete floors slabs. The repeating arched sections of these give an undulating effect to the ceilings of the office spaces. The top floor office spaces have the exposed steel roof structure above with central rooflights, and timber cladding to the undersides of the roofs forming the ceilings. The walls on the top floors are also clad in timber.
The external stair turrets have spiral stairs of steel and open treads with simple handrails. The stairs stand free of the surrounding wall structure, and rise to the caps which have the exposed mechanism for raising and lowering. Where the stairs are internal, they have concrete walls.
