The triangular plan form of Computer Associates’ parkland headquarters by Blair Associates offers a luxurious office idyll for the company’s executives
As I sat on the 08.14 fast service from London to Oxford I recalled the immortal, pre-war lines from John Betjeman:
‘Come, friendly bombs, and fall on Slough It isn’t fit for humans now’ Not the best advertisement maybe, but as it happened, Slough’s town centre was not on my itinerary. I was here to visit Blair Associates new Computer Associates’ headquarters on the outskirts.’The best building in Berkshire, ‘was my taxi driver’s unsolicited comment.
As we rounded the corner I was immediately disabused of Betjeman’s versified notion that ‘there isn’t grass to graze a cow’. Despite being flanked by the M4 and Heathrow Airport the headquarters is on a wonderful greenbelt site, set in the magnificent pastures of Ditton Park.
Driving into the site, past the security gates, we headed towards the prow of a green glass building of impressive proportions: low rise and extending into the distance. A thunderous fountain in a turbulent pool and a projecting canopy announce the main entrance. The front elevation is deceptively linear and the plan form only becomes apparent externally from the rear, where the massing of the building appears to be even more than it actually is. There are some very interesting games being played out here.
The plan is of two overlapping triangles, with the reception and control room at their intersection. The building is mirrored around this central hub and an explicit symmetry resonates throughout the building; as a design guide and as a functional device. However, there are many internal and external asymmetries, sufficient to provide visual interest, a sense of location and fine human touches to the office paradigm.
The entrance atrium connecting the visitor and employee entrances is a full-height glazed space with delicately handled flashes of colour.
The roof glazing to the bold circular rooflight is held almost horizontally on noded armatures extending out from the white steel structure.
In the bright sunshine, this space was very warm, though the gentle trickle of internal fountains psychologically cooled the air. The flank wall on one side has been cut away to accommodate the main access stair and the shop. This is no office tuck-shop; selling a formidable array of champagne, fresh flowers and Belgian chocolates, to ‘placate the spouse after working late’. In what other office would you have a shop with vacuumpacked, grilled, dried aubergines and jars of wild fennel sauces or a cash machine in the lobby?
The mezzanine’s glass balustrade is simple and effective, providing an unobstructed view to the central core below and out over the grounds. The internal colours seem more pronounced from this vantage point.
Because of the building’s deceptive geometry, there is always a surprise or two around the corner - although as a visitor it was nice to know that all routes led back to the central core. The lift area itself is consistently demarcated on each level in black, with a lower height ceiling and beautiful light fittings which reflect the form of glass support nodes in the main reception.
The majority of the 920 staff are housed within the body of the north and south triangles, separated into technical wings and development/sales wings respectively.The open-plan floors are divided into neat packages of personal workstations, break-out spaces, hot-desking zones and meeting areas.
Every morning fresh pastries and fruit are delivered. If the staff need to work off breakfast they can go to the fully-furnished gymnasium on the first floor or the adjacent sprung-floor aerobics and boxercise room.
The restaurant is in the hollow at the centre of one of the triangles (the other hollow is landscaped into a sedate Japanese Zen garden). From contemplating one’s navel to contemplating the menu, this place is a pleasure to be in. It is a proper restaurant, as much a place for doing deals as for eating out. Surrounded by glazing, with a bank of internal office spaces looking over the full-height arena, the restaurant combines the dynamism of a continental street cafeteria with the comforts of being indoors. Unfortunately, Computer Associates operates a cashless payment system, which provided much embarrassment for me at lunchtime, when I had to rely on the kindliness of a passing executive.
A crashing glass-block staircase divides the restaurant space. Opposite, children’s artwork gives a clue to the creche facilities beyond. This is no ordinary daycare.As part of the Montessori Child Development Centre, there are 12 full-time teachers employed to look after the 28 children within a high-quality pre-school environment.
The play equipment would be the envy of any cash-strapped local authority and children also have the use of the in-house, state-of-the-art games and hardware.
The private reception facilities situated alongside the restaurant are exuberant. Deep blues and rich wooden tones vie with the relentless ceiling and floor grid. The chequerboard carpet in the corridor angles away from the line of motion.
Commissioned artworks by two local artists, which pepper the walls throughout the building, are showcased between etched glazing panels. As the curved wall widened out I found myself in a workspace-cum-fairground. Curved walls, halfheight panels, candy coloured partitions, circular holes and free-form workbenches create an excitSERVICES The building was designed as a bespoke corporate headquarters, although the M&E systems were initially designed to a Category A layout to enable Computer Associates to have more time to develop its space layouts.
The basic elements of space utilisation were known at the onset of the design and these included general office areas, a 400-cover kitchen and dining area, a creche, fitness centre and central data centre. The M&E plant was selected to cater for the eventual uses of the building, which were to be detailed during the Category B design.
To maximise the usable floor area and satisfy planning height restrictions, the main M&E plant was put into two remote plantrooms immediately adjacent to the building. Underground trenches connect the services from the plantrooms to the building. In addition, the main air handling units were placed within recesses over the stairs to conceal them from view and to conserve usable space.
The chiller plant incorporates three 1,500 kW air-cooled chillers. The standby generator plant incorporates two 100 kVA generators and two 750 kVA generators which currently enable the data centre, small power distribution, lighting and essential HVAC plant to remain in operation during a power failure. The switchgear is configured and sized to enable larger-capacity generators to be ‘plugged in’ should the essential power requirement increase.
The kitchen is served by a two-speed dedicated supply air handling unit and extract system, pulling air through the dining and servery areas. The dining area is in the north block atrium, which has been provided with natural ventilation via automatic opening ventilation louvres incorporated into the facade glazing and glass atrium roof.
The creche and fitness centre were served by dedicated supply and extract plant and air conditioning systems.
ing arena for one-to-one meetings, software previews, and talk-throughs. A small ante-room contains a marble-topped counter, bar stools and an expresso machine. I half expected to see a Wurlitzer in the corner. This area culminates in a 20-seater screening room; but there are no couch potatoes - this is very much a dynamic company.
The business of Computer Associates - creative thinking - demands interactive stimuli and the opportunity for chance meeting and informal gatherings.And opportunities present themselves at every turn; wide staircases with people chatting; broad landings with small groups of staff congregating; and deep-plan office floors carefully designed to facilitate large groupings or small networking spaces. Michael Blair, of Blair Associates, says that this is deliberate: ‘Communication between departments and floors is encouraged via the stairs and established internal avenues in order to encourage opportunity problem-solving on a large scale.’
Long access corridors, which are the staple of all office developments, and are always daunting to the designer, have been handled well here.
While the office spaces and meeting rooms are arranged to face into the triangular atria, the corridors run around the outside affording views onto the park. However, because of the floor to ceiling glazing both internally and externally, it is possible to look through the offices into the atria from the corridor.
Glazing to the outside and between the two corridors and offices is remarkably well sound insulated, with the corridor creating an additional buffer to external noises.
Blair Associates has also been retained to restore the adjoining listed manor house which dates back to 1817, and to unify the grounds into a naturalistic parkland and moat as envisaged by Capability Brown in 1768. Recreating avenues of limes, oaks and elms is a long-term goal that will provide an exquisite link between the manor house and Computer Associates’ headquarters.
Visiting on a glorious summer day, with the heat haze rising over the stair towers, dragonflies humming in the undergrowth and massive Boeing 747s shimmering overhead, all that was missing was a picnic hamper and my thumbed copy of Betjeman’s collected works. As the taxi drove out of the gates taking me back to reality, I passed the wheezing staff who had made the 10 minute walk off the no smoking site, to have a quiet cigarette alongside the M4.
In basic terms the building on plan comprises of two large triangular frameworks, with the points of their hypotenuses touching, creating overall a 225m long three-storey high concrete frame on a 9.0m x 9.0m grid. It features exceptionally fine exposed concrete perimeter soffits and mirror-like finishes to circular columns clad entirely in a structural glass envelope.
Only one movement joint was provided on plan, splitting the two triangles and separating almost 25,000m 2of 400mm thick flat slabs, supported on 600mm diameter columns.
Thermal stresses were the governing factor in the design of the structure, which was analysed using 3D finite element analysis and modelling software.
Large concrete pours were achieved through careful attention to detailing of the 1850 tonnes of high tensile reinforcement, utilising off-site fabrication over the two hundred or so column heads wherever possible.
The building is externally clad in glass curtain walling with the exception of the main entrance facade. This features 12m high vertically-hung planar glazing supported by elegant tubular bowstring trusses.
The central atrium roof structure is spanned by 30m long sloping tubular steel bowstring trusses with alternate long and short cantilevering arms, supporting 3.6 x 1.8m glazing panels, each picked up on six spider fixings per panel. The trusses were fully adjustable for on site line and levelling, via jacking through the turnbuckles of the bottom chords.
External stair cores featuring a full-height glazing wrap around a 12 m high vertically cantilevered stair structure, propped laterally by a horizontal tubular girder at roof level, projecting out from and anchored back to the main frame.
More than 1,000 tonnes of exposed steelwork was used to support the glass envelope, employing the highest standard of fabrication and anti-corrosion protection available.
External civils works involved surface water attenuation to balance the storm water run off volume from the circa 800-space car park, prior to discharging to the local watercourses as well as new road bridges, pipe bridges and environmentally-friendly culverts.
Considerable cost savings were achieved through soil remediation over traditional methods of dealing with poor quality surface soils beneath the vast car park areas.
Frank Bates, Whitby Bird & Partners
Costs based on final account
SUBSTRUCTURE FOUNDATIONS/SLABS £62.20/m2 Mass concrete pad foundations with reinforced concrete ground floor slab including base for reflecting pool. Ground floor slab tanked with waterproof membrane. Services trenches with precast concrete access formed with slab
SUPERSTRUCTURE FRAME AND UPPER FLOORS £90.35/m2 Reinforced circular concrete columns with flat slab floor and roof incorporating edge beams ROOF £76.57/m2 Hydrotech inverted roof covering on screed to falls.
Fabricated circular hollow steel trussed atrium roof with double-glazed planar units laid sloping. Circular glazed rooflight to front entrance. Glazed perimeter parapet to match curtain walling to main elevations
STAIRCASES £24.70/m 2Steel accommodation staircase to main reception with stainless steel handrails and glazed balustrade panels. Steel escape staircases with stainless steel handrails and part glazed and part perforated extruded aluminum balustrade panels
EXTERNAL WALLS, WINDOWS AND DOORS £224.39/m2 Fully glazed panelised curtain walling system to all main elevations and escape stair enclosures. Slate plinth to building perimeter. Glass block walls to internal atrium stair and stair to courtyard. Structural glazing to main entrance screen and canopy
INTERNAL WALLS AND PARTITIONS £88.60/m 2Blockwork walls to kitchen and risers. Metal stud partitions to meeting and ancillary office areas.
Frameless fire-rated glazed screens to floor lobbies.
Frameless glazed fronts to meeting rooms
INTERNAL DOORS £15.71/m 2Softwood painted doors in split metal frames.
Frameless glazed doors within fire rated screens
INTERNAL FINISHES WALL FINISHES £8.72/m 2Emulsion painted plasterboard walls. Half-height ceramic tiling to WCs. Full-height ceramic tiling to kitchen
FLOOR FINISHES £75.27/m 2300mm medium-duty raised floor with carpet tiles throughout office areas. Flooring to main entrance reception 450mm heavy-duty raised floor with bonded laminate finish to data room. Vinyl flooring to WCs with studded rubber flooring to staircases and landings. Ceramic tiling to restaurant and kitchen
CEILING FINISHES £38.82/m 2Hinged perforated-metal concealed-grid suspended ceiling to offices. Sloping plasterboard bulkhead to perimeters
FITTINGS AND FURNISHINGS FURNITURE - OCCUPIER’S WORKS £2,500,000 Entrance reception desk. Fully fitted themed restaurant including kitchen and servery equipment.
Fully fitted marketing suite (VER). Fully fitted fitness centre. Fully fitted daycare centre. Solar controlled blinds to all elevations. Signage
SERVICES SANITARY APPLIANCES AND MECHANICAL INSTALLATION £281.80/m 2White glazed sanitary ware installations. Independent four pipe fan coil and VAV air conditioning systems with supplementary cooling to Data centre.
Mechanical ventilation to WCs tea rooms, showers etc.
Underfloor heating to daycare. Extract systems to restaurant and kitchens.Controls and BMS to mechanical services installations ELECTRICAL SERVICES £319.23/m 2HV transformers and switchgear LV switchgear and distribution boards. Standby generator installations comprising four 1250 KVA generators Cat 2 lighting throughout office area with specialist lighting to other areas.Underfloor busbar power fire alarms, power for mechanical services. Construction of external generator and switchgear pavilion
LIFT AND CONVEYOR INSTALLATIONS £7.77/m 2Bank of four passenger lifts and one goods lift serving three floors
PROTECTIVE INSTALLATIONS -OCCUPIER’S WORKS £650,000 Fastlane security to reception. Proximity card access control system. CCTV installation to car park and buildings
COMMUNICATION INSTALLATIONS - OCCUPIER’S WORKS £450,000 Cat 5 data and voice cabling installation
PRELIMINARIES AND INSURANCES PRELIMINARIES, OVERHEADS AND PROFIT £206.09/m
EXTERNAL WORKS LANDSCAPING, ANCILLARY BUILDINGS £2,550,00 Tarmacadam site roads and car parking. Underground drainage including pumped drainage reservoir. New incoming services. Reflecting pool to front elevation of building
LANDSCAPING - OCCUPIER’S WORKS £600,000 Topsoiling, seeding, turfing and planting to site.
Daycare garden and play area. Multipurpose games area cost summary Cost per m 2Per cent (£) of total
SUBSTRUCTURE 62.20 4.09
SUPERSTRUCTURE Frame and upper floors 90.35 5.94 Roof 76.57 5.04 Staircases 24.70 1.63 External walls, windows and doors 224.39 14.76 Internal walls and partitions 88.60 5.83 Internal doors 15.71 1.03 Group element total 520.32 34.23
INTERNAL FINISHES Wall finishes 8.72 0.57 Floor finishes 75.27 4.95 Ceiling finishes 38.82 2.55 Group element total 122.81 8.07
SERVICES Sanitary appliances and mechanical installation 281.80 18.54 Electrical services 319.23 21.00 Lift and conveyor installations 7.77 0.51 Group element total 608.80 40.05
PRELIMINARIES 206.09 13.56 Costs supplied by Nigel White, AYH
Blair Associates www.blairaarch.com
Whitby Bird & Partners www.whitbybird.com
Flack and Kurtz (UK) www.flackandkurtz.com
John Mowlem & Co www.mowlem.co.uk
TENDER DATE October 1997
START ON SITE DATE Spring 1998
CONTRACT DURATION 18 months
GROSS EXTERNAL FLOOR AREA 23,225 m2
FORM OF CONTRACT JCT80 TOTAL COST £41,325,000 CLIENT Computer Associates ARCHITECT Blair Associates:
Michael Blair, Christopher Firth, Martyn Pritchard, Doug Reid, Michael Harwood
QUANTITY SURVEYOR AYH Partnership
PROJECT MANAGEMENT AYH Partnership
STRUCTURAL ENGINEER Whitby & Bird
SERVICES ENGINEER Flack & Kurtz (UK)
MAIN CONTRACTOR John Mowlem US
BRIEFING ARCHITECTS Spector Group
SUBCONTRACTORS AND SUPPLIERS structural frame, external works, culvert crossing, pumped sewer main, water attenuation O’Keefe Construction (Greenwich); concrete frame Silver Construction; curtain walling Witte (UK), De fries Robbe; atrium roof & structural glazing Space Decks; glass blockwork Roger Wilde; main roof Prater Roofing; louvres and plant pavilions Kingfisher Louvre System; architectural steel and stairs Delta Fabrication; Alucabond cladding Supreme Contracts; architectural metalwork P&R Precision & General Engineering; internal atrium Birchdale Glass; steelwork to nodes Tubeworkers (Structures); lifts Otis; internal curtain walling Unilock; suspended ceilings Carlton Ceilings & Partitions; raised access floors Hewetson Floors; carpets Interface Europe; granite floor & wall tiling Grant Ameristone; WC cubicles Houston Cox Carpentry; blinds Louvre Blind Company; glazed partitioning Optima Partitioning