Pearl Centre

The Pearl Centre is a commercial office complex built between 1989 and 1992 for Pearl Assurance Ltd. Chapman Taylor Partners designed the building with Ronald Farquharson Partnership as structural engineers.

Construction and Materials

The building employs composite steelwork construction with a pantile roof covering and glazed roofs over the internal atria. The roof towers are clad in lead. Exposed eave beams and hardwood soffit boards feature prominently in the design. The office blocks and restaurant have glazed curtain walls set in mahogany framing, while the entrance, stair towers, computer hall, training centre and car park are constructed of buff-coloured brick with French limestone dressings.

Plan and Layout

The complex comprises three square-plan office blocks—named Orton, Middle and Nene—arranged along an east-west axis and linked at their corners. These are supplemented by an attached computer hall, restaurant block and training centre, all positioned above a square-plan underground car park. Together, the three office blocks provide 37,500 square metres of space across three storeys, each organised around a central open-sided atrium.

At the south corner of the central Middle block lies an entrance courtyard at first floor level. A central entrance foyer opens from this courtyard, with the computer hall attached to its north-east side, the restaurant block to its north-west side, and an L-plan training centre at its south-east corner. Beneath the computer block, restaurant block and training centre sits the two-deck covered car park, measuring 28,800 square metres and accommodating 1,500 vehicles. Access to the car park is provided from the south-west or north-west sides. The main road through the site defines the boundary of the square-plan car park and passes through the central office block at ground floor level.

Exterior: Office Blocks

The three linked office blocks each stand three storeys high beneath hipped pantile roofs. Circular-plan glass roofs crown their central atria. The eastern Orton block and western Nene block each feature three square-plan extraction towers on their roofs, topped with shallow-pitched roofs and lead-clad walls.

Each floor displays distinctive elevational treatment: the first floor is jettied over the ground floor, while the second floor steps back. Exposed eave beams at ground floor level and deep eaves with hardwood soffit boards at first and second floor levels create a brise-soleil effect for each storey. The glazed curtain walls are mahogany framed, with first and second floor windows incorporating slender Mackintosh-inspired glazing. The lower portions of the first floor windows feature yellow, green, red and blue panes that conceal internal air-conditioning units.

At the centre of each elevation and at the junctions where blocks link, Italianate stair towers rise, constructed in buff-coloured brick with French limestone dressings. Around 2005, a single-storey glazed entrance lobby was added to the south elevation of the Nene block to provide a separate entrance.

Exterior: Entrance Courtyard

The entrance courtyard at the south corner of the Middle block provides the main entrance to the buildings at first floor level. A round-arched recessed door surround features three continuous orders carved from French limestone and contains stainless-steel framed revolving doors flanked by two side doors beneath a fanlight. The arch's keystone bears the carved crest of the Pearl Assurance company. An octagonal-plan glazed roof over the entrance hall is concealed behind the parapet.

Exterior: Computer Hall and Restaurant Block

The attached computer hall (to the south-east) and restaurant block (to the south-west) share similar elevational treatments. Both stand two storeys high with steeply-pitched pantile roofs over the first floor and a band of curtain glazing at second floor level beneath shallow-pitched lead-covered roofs.

The first floors differ in treatment: the restaurant block has glazed curtain walls in mahogany framing, whilst the computer hall features buff-coloured brick walls with French limestone dressings. The south-east elevation of the computer hall, facing the memorial garden, displays four bronze plaques commemorating company employees who fell in the Second World War (1939-45).

The south-west end of the restaurant block's roof carries a square-plan glazed lantern with a shallow-pitched lead-covered roof, illuminating the double-height dining hall below.

Exterior: Training Centre and Linkages

In the south-east corner of the entrance courtyard, the single-storey training centre presents glazed curtain walls in mahogany frames to the courtyard interior and buff-coloured brick walls with French limestone dressings to the exterior. The restaurant block and training centre connect at first floor level via a covered walkway whose roof is supported by two buff-coloured brick blocks containing a pumping room and stairs to the car park.

The south-west end of the restaurant block and the south-east and north-east corners of the training centre feature outdoor terraces with curved balustrades. These balustrades comprise red oriental-inspired panels depicting four-petal flowers within square borders.

Exterior: Car Park

The square-plan two-storey covered car park beneath the entrance courtyard, restaurant block, computer hall and training centre has buff-coloured brick walls and French limestone dressings. Circular-plan French limestone turrets mark the south-west and south-east corners. The ground floor walls incorporate closed sections with vertical slatted openings and open sections with Mackintosh-inspired red mesh screens.

The upper level of the car park is accessed at ground-floor level on the south-west side through segmental entrance and exit arches flanking a flight of steps leading to the first-floor physic garden and entrance courtyard. The lower level is accessed at lower ground floor level on the north-west side through flat-arched entrance and exit openings.

A segmental arch on the south-west elevation of the Middle office block allows the main road to pass through the building at ground floor level, exiting via its south-east elevation.

Interior: Main Entrance Foyer

The main entrance from the entrance courtyard brings visitors into the building at first floor level. The double-height octagonal entrance foyer rises 10 metres and is vaguely Romanesque in style. Its west, north and east sides are bounded by a screen of carved round-arched arches with continuous orders rising from grey marble bases.

The ornate marble floor displays a symmetrical star-shaped pattern. At its centre, a column supports laminated-timber trusses and an octagonal glazed roof. Above the entrance, a second-floor waved gallery provides access between the computer hall (to the south-east) and restaurant block (to the south-west).

From the foyer, visitors can proceed south-west to the restaurant block, north-west to the atrium of Middle Hall, or south-east to the computer hall. Proceeding straight through the foyer, visitors pass through a groin-vaulted cloister-like link to reach the Middle Hall atrium.

Interior: Middle Hall and Connecting Atria

The Middle Hall atrium is symmetrical in its architectural features and decoration, featuring a blue and gold patterned marble floor, informal seating areas, twin staircases rising to the second floor, and a circular glazed roof. Conference rooms, a medical suite, and half-glazed rooms (formerly housing a convenience shop, hair stylist, bank and travel agency) open off the atrium.

From Middle Hall, visitors can continue diagonally along an internal street east to Orton Hall or west to Nene Hall, each with its own central open atrium. The three atria were designed to possess distinct characters, described by Chapman Taylor Partners as resembling 'a string of beads' allowed to be different colours, sizes or shapes. Each hall's centrepiece—the work of various designers within the architectural team—reflects the variety of different departments (now companies) occupying the building.

Orton Hall displays Japanese character, with a simple formal garden set into the floor beside an arrangement of copper screens featuring cut and burnished designs. By contrast, Nene Hall was decorated with specially-commissioned pots by Alan Caiger-Smith (now in storage). Whilst Middle Hall has two staircases, Orton Hall and Nene Hall each feature a single corkscrew staircase—Orton rising clockwise, Nene anticlockwise.

Interior: Office Spaces and Building Systems

The three atria were designed to be surrounded by open-plan offices, providing employees with natural ventilation and light whilst maximising views of the gardens. Sophisticated ventilation techniques and sprinkler systems were designed to minimise the need for fire safety divisions, enabling totally open and bright floors. When the building became tenanted around 2005, glazed partitions were introduced to the offices flanking the atria to provide acoustic buffering and security.

The office spaces are designed on 9-metre grids, divided into 750-millimetre floor tiles, with workstations designed on the 750-millimetre grid. The raised floor accommodates electrical wiring, computer cables and telephone lines, whilst the suspended ceiling accommodates air conditioning.

The Building Management System was designed to maintain an ambient temperature of 21 degrees Celsius, controlling humidity and air flow. Fresh air is fed from air-handling units located in the nine stair tower plant rooms, where it is filtered and heated or cooled, humidified or dehumidified, then supplied via ceiling fan coil units in the inner zones of the building or via sill level units around the perimeters and atria. These sill-level units are clad in maple with Mackintosh-inspired mahogany inlay. Air rises through the building and is extracted by roof top fans. A separate system for smoke and fume extraction is provided in the lead-clad ventilation towers of the roof.

Interior: Restaurant Block

The restaurant block was designed to seat 600 employees at any one time. The double-height dining hall at the south-west end features chamfered stepped corners stepping down to square-plan columns clad in maple with mahogany inlay and topped by pyramidal uplights. The columns are linked by decorative metal and wooden screens that divide the vast space, whilst coved ceilings provide variety. Near the servery, low-level inlaid partitions articulate space, with spherical lights in claw-like fixtures attached to the corner posts.

The second floor of the restaurant block contains a large meeting room featuring inlaid doors, foldable partitions, coved ceilings, and inlaid cupboards on the south-west wall.

Interior: Computer Hall

The computer hall features a large open-plan office spanning the majority of the second floor. From the first floor of the computer block, a large stair hall adjacent to the entrance hall provides access to the two car park levels below.

For data protection and security reasons, it was not possible to access the first floor offices of the computer hall, the offices of Orton Hall or Nene Hall, or the interior of the training centre in January 2019.

Subsidiary Features: Water Feature

The centrepiece of the first-floor entrance courtyard is a slightly raised Moorish water feature. An octagonal-plan statuary island stands within an eight-pointed star-shaped pool and is bordered by two eight-pointed star-shaped paths divided by water channels. Diagonal paths extend from the corner points of the outer star, dividing four grass lawns gently sloped toward their outer edge and bounded by granite kerb stones. Each path terminates in a low square-plan fountain, with two steps descending to silver granite steps of pedestrian crossings at carriageway level.

At the centre of the water feature stands a 4-metre bronze figurative sculpture of St Margaret of Antioch by Michael Sandle RA (born 1936), a distinctly modern reworking of the saint found on the company's crest. The Christian daughter of a pagan priest, St Margaret was reputedly imprisoned for her faith and devoured by Satan in the form of a dragon before utilising her cross to escape. Margarita (Margaret) is Latin for pearl, hence the association of the saint with the company name. The saint holds a pearl in her right hand, a palm branch (an emblem of honour and symbol of success) in the left hand, with a dragon lying at her feet.

The paths are crafted of Cornish grey granite paving, and the water channels and pool are constructed of black slate paving.

Associated Listed Features

The war memorial in the war memorial garden, dated 1919 and designed by Sir George James Frampton RA, is dedicated to the fallen of the First World War. Four accompanying bronze plaques are dedicated to the fallen of the Second World War. This memorial is separately listed at Grade II* (NHLE 1462803).

The designed landscape in which the Pearl Centre stands was designed by Professor Arnold Weddle of the Landscape Research Office and is registered at Grade II (NHLE 1462808).