Ugly Betty probably doesn’t crop up at many initial lighting concept discussions, but nailing the exact aesthetic that PricewaterhouseCoopers wanted was a crucial starting point.
‘It was about seeding debate,’ says Mark Ridler, lighting director of BDP. ‘We quickly settled on “understated excellence” as the guiding principle. It was very important to support the client’s brand, exuding quality of service without overt extravagance – slightly domestic but very classy.’
And it was essential to achieve that within strict energy parameters. PwC was gunning for, and achieved, the goal of having the first building in the capital, and the first major office in the UK, to be awarded the Breeam ‘Outstanding’ rating. ‘I can’t emphasise enough how important sustainability was to the client,’ says Ridler.
Helping to achieve this is the ‘technology harvest’ principle that BDP adopted about four years ago. PwC was keen to use LEDs, but with the rapid pace of LED development and the time between spec and installation, which can be three or four years, the equipment is invariably outdated by the time it is installed. ‘What we say is that in three years there will be more efficient kit out there, but if you draw the line now you won’t reap the benefit of that,’ says Ridler.
In 2009 the LED fittings available were not up to snuff. So BDP wrote a performance specification based upon products available at the time (including lumen package, efficiency, Ra, beam angle, colour temp, dimming and so on) and stipulated a technology harvest review shortly before the ordering deadline.
‘We tracked the technology and when Xicato brought out its engine we knew we could deliver the brief and provide the energy efficiency the client was looking for. The Xicato engine in DAL luminaires is used extensively throughout the project, in combination with other LED products. That decision was made four weeks before the button had to be pushed on the orders. We took it right to the wire.’
Control is also obviously crucial to efficiency, and in addition to absence/presence detection, daylight control and scene-setting, individual users also have control of local lighting in the open-plan office areas using their laptops. PwC operates a hot-desking system, so when staff arrive in the morning they have to book a desk. As part of this process the building tells the laptop where it’s going to be and gives it a degree of local lighting control.
However, this is tempered by a ‘my space, your space, their space’ approach to avoid conflicts over diverging preferences and extremes of contrast across the office space. Control is pooled among four people – if one person wants the lighting full on while another wants it off, a compromise level of 50 per cent is set. There is also a limit to the amount of override possible when controlling, for example, daylight-linked fittings.
Energy and aesthetic aims
Underpinning both energy and aesthetic aims are PwC’s working practices, which had a profound effect on interior and, therefore, lighting design. The company assembles teams at short notice for varying periods, and space has to be highly flexible and easy to configure quickly. The open-plan floors were split into a variety of different environments to accommodate this mutable working style.
‘This was far from a Cat A blanket provision with the odd reception desk,’ says Ridler. ‘It was about meeting this need without making everything bland, injecting atmosphere – in fact a variety of atmospheres – so you didn’t feel you were walking into a prairie of Cat A.
‘The challenge for such a large project is to avoid a relentless application of one environment,’ continues Ridler. ‘Occupants feel disorientated and alienated. Our aim was to create individual environments and a variety of working modes – informal booths, break- out and small meeting spaces, special team areas, staff refreshment points, formal meeting rooms. The team leaders have reported that they feel that each working space is appropriately scaled and that allows ownership while providing flexibility.’
Working to be flexible
This flexibility means that the building works hard and the lighting needs to support this. For example, partner offices can be secured and used as meeting rooms when partners are absent. The eighth floor is for clients and can be configured as individual meeting rooms, pre-function and reception, or the walls removed and set for fine dining.
The seminar suites typify this approach. They are linked with walls that can be moved to create spaces for formal dining, lectures, meetings, seminars and training. The lighting had to allow for this level of flexibility with partition control and scene setting, all helped by an early decision on the part of the client and electrical engineer to fit Dali throughout the building. The carefully configured grid of LTS’s Light Channel creates a soft ambient light pepped up by accenting from DAL Xicato adjustable downlights. These can be used alone for the dining setting, for instance. ‘The strategy is similar to that deployed in hotels,’ says Ridler.
‘We went for this combination of soft wash and accenting pretty much throughout, manifested in different ways depending on where you were. For instance, the meeting rooms have the same linear light providing a wall wash that gives good people and room light, and then there’s accenting down on to the working plane. It gives a soft contrast so you have visual interest but also energy efficiency.’
The twin demands of flexibility and an attractive interior aesthetic – Conran restaurants were an inspiration – drove much of the lighting down a decorative route. Where possible lighting is integrated – as in the extensive use of Light Channel – but Ridler says: ‘The large degree of flexibility required means there aren’t many banquettes, credenzas and those kind of fixed three-dimensional elements into which you can integrate light in a minimalist way.’
But that became a virtue, says Ridler. ‘The good thing about decorative fittings is that they break down the volume.You’re not always looking at a 3m- high slice of thin air with walls and windows a long way away – they help partition the space in a soft and flexible way.’
Colour temperature further delineates different areas, with 3000K sources used for spaces such as social break-out areas, 3500K in the open-plan office and 4000K in corridors.
‘The real design challenge was to get the functionality/sustainability combined with the variety of atmospheres that we felt that it needed,’ says Ridler. ‘A lot of hotel techniques were applied. It’s been a fascinating project from that point of view.’