Built on a former gasworks (appropriately), Scottish Gas’ HQ is an elegant and energy-efficient addition to Edinburgh’s rapidly changing waterfront. Architect Foster and Partners, environmental engineer Battle McCarthy and cost consultant Davis Langdon explain how they did it.
<B><font size="+2">Key points</font></b>
10,500 m2 speculative headquarters office building
Granton, north Edinburgh
Flagship development in ForthQuarter 28 ha mixed-use regeneration scheme
Striking landmark building with fully glazed facades and solar-shading screens of horizontal aluminium tubing
- “Excellent” BREEAM rating for low environmental impact
- Chilled beams and displacement ventilation for low-energy environmental control
- Superior call centre interior for 1150 staff raises productivity and improves staff retention
- High-density layout at 6 m2 per person made acceptable by daylight, feeling of space and well-organised desks
- Construction management adopted for fast-track construction and design input from specialist contractors
£1930/m2 unit construction cost, including full tenant’s fit-out and external works, is good value for a high-specification office building
Eighteen months, including tenant’s fit-out, to September 2003
<B><font size="+2">The client’s brief</font></b>
The client, SecondSite Property Holdings (formerly the property division of BG plc) set out to develop a speculative office block as the first building in its regeneration of a large former gasworks overlooking the Firth of Forth. SecondSite asked for a flexible, low-energy office building of 10,500 m2 that could be partitioned and internally reconfigured to suit a range of tenants and uses, including a corporate headquarters. The first tenant, Scottish Gas, has fit out the building as its call centre and headquarters.
<b><font size="+2">Regeneration masterplan</font></b>
The entire former gasworks is being regenerated by SecondSite Property and masterplanned by Foster and Partners. The 28 ha area, now known as the ForthQuarter, overlooks the Firth of Forth at Granton in north Edinburgh. This regeneration scheme is one of three along the city’s waterfront.
At the ForthQuarter, a heavily polluted, toxic no-go area is being transformed into an attractive clean neighbourhood with utilities, public parks and transport infrastructure, including a new tram link to the city. A vibrant, mixed-use community is planned that will bring together 2000 homes, 70,000 m2 of office accommodation, 10,500 m2 of retail and leisure space and a college campus.
<B><font size="+2">Architectural design</font></b>
As designed by Foster and Partners, the four-storey Scottish Gas building has many of the qualities of both a public building and a corporate headquarters. The result aims to combine an efficient, functional workplace accommodating a large number of employees at high density, and an inspiring work environment which conveys a message of valuing the workforce and encouraging loyalty, teamwork and productivity.
The entrance is on the south frontage, where a deep recess is lined on either side by blue glass laid over concrete. The shiny, vivid blue glass draws employees in from a new public plaza in front of the building and exudes an atmosphere of elegance and formality as they arrive for work. A lofty entrance hall leads into an atrium capped by a white glass lantern. Diffused daylight spreads through this lantern into the space below, accentuating the airy volume.
The ground floor accommodates meeting rooms, administration, IT, occupational health and a 220-seat staff restaurant opening into the atrium. As this is the first completed building on the site and there is, as yet, little activity in the area, good staff facilities are essential, so a shop and vending and cash machines have been provided. Lifts and cantilevered staircases take staff up to the three call-centre floors, which are arranged as open-plan workspaces on either side of the atrium and command views through the building.
The exterior of the building announces itself as a striking local landmark. Constructed on a concrete frame, the fully glazed facades are surrounded on all four sides by banks of silvery sun-screens.
Made from specially manufactured elliptical aluminium tubing, the sun-screens run in horizontal lines and are suspended from flat vertical bars that drop from the roof to the foot of the building. As well as providing shade, the sun-screens give strong visual definition to the architecture. They sit proud of the glass facades, but run straight across the entrance recess, so that they form a rectangular veil over the irregular U-shaped building enclosure. The spacing between the horizontal tubes is not uniform: the lines loosen up on each floor at eye level so as not to impede views, and are grouped closer together where floors and ceilings occur. In all, some 8 km of tubing were used to form the shading system.
<B><font size="+2">Procurement and cost control</font></b>
The choice of procurement route was strongly influenced by pre-letting the building to Scottish Gas, which wanted to move in early. The requirement for accelerated completion emerged early in the design stage, at RIBA stage C, and was a major factor in the decision
to adopt construction management procurement. Following the appointment of the construction manager in June 2001, work commenced on site in March 2002.
Specialist contractors were involved at an early stage, also as a
result of using construction management. The project features a number of innovations and this early input was important in devising high-quality, cost-effective solutions.
A good example of this involved the passive chilled beams,
which were adopted in place of conventional four-pipe fan coil
air-conditioning. In this case, the specialist contractor was required
to meet institutional performance standards, to integrate the system with the office lighting installation, to accommodate future office partitioning requirements and to achieve very low noise levels. Installation costs also had to be kept low. Typically, passive chilled beams have higher initial capital cost than fan coils, often in the region of an extra £50-60/m2 of net internal floor area, though this reduces to an extra £10-20/m2 once savings on ceilings are taken into account. Although such a solution is still marginally more expensive, savings can be made in running and maintenance costs.
The tenant’s fit-out was rolled together with the landlord’s fit-out as part of the main construction management contract, and this enabled the tenant to move in several months early. The developer paid trade contractors for both tenant’s and landlord’s fit-outs and was later reimbursed by the tenant, which had formerly been part of the
The predicted final account costs, including tenant fit out and external works, are in the order of £1930/m2. In its landmark design, undercroft parking, high occupational densities of one person to
every 6 m2, high quality office environment and BREEAM rating of “excellent”, the building delivers significant benefits to the client and
is very good value for money.
The shell-and-core, category A and external works element of the project total £1355/m2. There are no published benchmarks for buildings of this specification and quality, and if the cost drivers associated with the undercroft, cooling system and high occupational density are taken into account, the project compares very favourably with more conventionally specified business park offices.
<B><font size="+2">Environmental design</font></b>
The environmental story of the building is as significant as that of the whole site regeneration. As designed by Foster and Partners working closely with environmental engineer Battle McCarthy, the building achieved the coveted “excellent” rating on the BREEAM scale. It scores highly on every aspect of its impact on the environment, from energy consumption, insulation and recycling, to the amount of energy expended in constructing and transporting materials, the proportion of materials drawn from sustainable sources, and the building’s integration with public transport.
Throughout the building, a pleasant and airy environment is achieved by a combination of passive chilled beams, displacement ventilation and the exposed mass of the building structure. This low-energy solution avoids the need for fan air conditioning. The fusion of architectural and environmental design led to ceiling rafts carrying chilled beams and lighting being floated within the coffered undersides of the concrete floor slabs. On the office floors, flat-screen computer monitors greatly reduce heat output.
As for the external envelope, high-quality “solar neutral” glass and the external sun-shading system deflect glare while admitting high levels of daylight. And a compact arrangement of efficient basement and rooftop plant helps keep both energy use and maintenance costs low, while still providing excellent back-up in case of power failures.
As tenant, Scottish Gas asked for its call centre to be fitted out as a high quality office environment within a standard budget, and with a high density of occupation of 6 m2 per person in a building originally designed for 10 m2 per person. Despite these constraints, the fit-out achieves new levels of quality and comfort for call centres.
The interior is designed to give flexibility for changing shifts, personal storage for each employee, and optimum use of space. The dense cruciform furniture layouts of enclosed booths normally specified for call centres were rejected as they provide little opportunity for staff to interact. Instead, continuous linear benches were developed with the furniture manufacturer to give the interiors a spacious feel and a clear definition of each team area. Personal computers terminals are arranged in banks at each end of the bench, from where they draw power and data from a bespoke cable management pod directly below. As well as giving easy access for maintenance, this reduces floor penetrations for cables to just two for 10 members of staff.
Each staff member is provided with his or her own storage space, which is combined into communal banks running between lines of desks. This gives each person a sense of identity and removes the stress of sharing desks over several shifts, as he or she can simply clear the desk at the end of each shift ready for the next person.
Each storey draws its identity from its own accent colour, which is applied to dividing screens between desks and to other selected areas against a neutral background. Staff members chose the colours from a set of options presented by the architect, and they were also consulted on the choice of loose furniture.
The informal break-out areas on the upper floors bring together the accent colours and loose furniture. These are situated on the bridges spanning the open atrium, where they benefit from the space and daylight of the atrium along with wide views across the building.
For Scottish Gas, the new call centre is a major step forward in working practice. The company has taken its staff into a light-filled building with all-round vistas that include the Firth of Forth, the Forth Bridge and Edinburgh Castle. And despite the high-density layout, it feels anything but cramped. Rather, with its good light, pleasant environmental conditions, splendid outlook, open-plan permeability, high ceilings and well-organised desks, it gives an impression of space.
The Scottish Gas HQ already looks likely to secure greater staff retention. After only five months of occupation, people say they feel more focused and work more effectively – and management reports that productivity is up.
Principal subcontractorsLilley Construction (sub- and superstructure), GIG Fassadenbau (facades), Cairnhill Structures (structural steelwork), ECG (mechanical services), Forth Electrical Services (electrical services), SAS International (ceilings)
SecondSite Property Holdings
Foster and Partners
White Young Green
Hyland Edgar Driver