APPLICATIONS editor John Bullock assesses the refurbishment of the lighting at the Argos headquarters in Milton Keynes.
The headquarters of the high street retailer Argos has seen a 30-year-old fluorescent installation replaced with modern cellular-style LED modular fittings.
The original lighting scheme for the Milton Keynes office was planned in the 1980s, when energy consultants were a rare breed and lighting was approved on the simple basis of its installed load.
The scheme was based around parallel lines of continuous recessed fluorescent modules, fitted with the inevitable Cat2-style louvres.
It was cutting-edge at the time and the company – now owned by supermarket giant Sainsbury’s – had every reason to be proud of it. But energy planning was on the horizon and would, eventually, make itself felt.
A changing and challenging world soon required more from a lighting installation than a switch-on first thing in the morning and, hopefully, a switch-off at the end of the day. And so a controls intervention was made to reduce energy demand. And that decision, welcome though it was, had a serious impact on the decisions taken with this latest refurbishment.
The benefits of an upgrade from a T8 fluorescent installation to LEDs should be straightforward enough and the energy savings should be there for all to see. But it’s a different matter if that fluorescent installation has been fitted with occupancy sensors. Once a lighting installation uses energy management, it makes the return on investment of any planned refurbishment difficult to achieve.
The low-hanging fruit of energy savings has already been gathered. And even the benefits of a shift to a more efficient LED installation makes a new scheme more challenging to achieve. Or does it?
There was something else going on with the original installation, beyond light planning based on installed load figures.
At that time, office lighting was assumed to deliver a uniform scheme, based on the assumption that no one really knew how the furniture layouts would be determined. It was a fundamentally inefficient approach to lighting design and, let’s face it, an approach that still hasn’t gone away.
The team behind the refurb included Peter Fordham of Sainsbury’s and the electrical contractor Halsall Electrical, who in turn hired the the former Sainsbury’s lighting specialist, now consultant at Urban Jungle Energy & Engineering, Simon Waldron.
Because the cost benefits of a new LED scheme were squeezed as a consequence of that control intervention of some 20 years ago, the designers and planners of the new scheme were forced back to the drawing board to find more efficient ways to illuminate an office space.
And from that point, it was a short step to embracing what’s been termed ‘localised lighting’ as the appropriate concept for the new offices.
Localised lighting works because it’s a fully-integrated approach to an office fit-out. There is an absolute connection between work station and luminaire, which calls for the interior space planning to be determined much earlier in the process.
If the lighting planner knows what’s to be lit then it sets the foundation for a far more efficient, and elegant, solution.
The result at the Argos head office is an exemplary demonstration of how a conventional office lighting scheme can be re-interpreted in such a way that working conditions are not compromised – if anything, working conditions are better – while energy controls delivers satisfyingly low consumption figures.
The office illumination is delivered by a series of fully recessed square modular fixtures, in this case the Rubix from Dextra, using the latest style of LED cellular optic; a way of grouping small downlight cells into a modular housing, thus delivering office-quality illumination in terms of both illuminance levels and glare control.
The modules are set-out according to work station layouts and no light production is wasted where it is not needed.
Each work zone is controlled via the latest generation of sensors, so daylight control, occupancy control and illuminance settings all work to ensure that energy consumption is reduced to a working minimum.
But there is another feature of the modern office that also benefits energy management. The introduction of the break-out space does not require the same levels of illuminance as a work station, so the more floor area given over to these flexible working spaces, the greater the potential for more energy efficiency.
It is better understood that employee comfort leads to a more efficient working environment and break-out spaces have led to a ‘softening’ of the office interior. Pendant fixtures with fabric shades provide an appropriate working level of light, while the visual improvements over the conventional office ‘box’ are plain to see.
The building itself is a rectangular footprint with a central atrium that rises up four levels from ground to roof.
A ‘light tree’ at each end of the atrium provides localised illumination to the surrounding tables and chairs, while the central reception desk is highlighted from the roof level. It is an approach that helps reinforce the human scale of the atrium space and brings a focus to the activity of the building, rather than the architecture itself.
In all, Sainsbury’s should be congratulated for creating an office building that, while still sitting firmly within the conventional understanding of what an office lighting scheme should be, has moved successfully towards an interior environment that complements modern working practices – and all within a cost framework that delivers a positive Return on Investment, while improving the office aesthetic and everyone’s working conditions.
- The Lighting for Workplace and Wellbeing Conference takes place on Wednesday 14 November in the lightspace arena at the LuxLive 2018 exhibition in ExCeL London. The conference is free to specifiers and end users. See the full programme HERE.