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The inTegraTion issue
hile the visual impact of integrated lighting is undisputed, there’s one area where many architects and lighting designers are prepared to sacrifice finished effect for ease of use – integrated ground-recessed lighting. Most lighting designers can reel off a long list of problems associated with in-ground lighting, including water getting into the fitting, installation problems, the amount of weight the luminaire can bear, surface glass heat, lack of optical control and maintenance, not to mention ensuring the luminaire is properly housed and sits in the ground correctly.
“The problem with anything in the ground is that it’s the most vulnerable place you can possibly put lights,” says Iain
Ruxton, design associate at Speirs + Major. “The classic thing that used to happen is that a contractor would open the lot and put lamps in, but when they went to put tops back on, dirt or grit got in and it didn’t seal again,” he says. “If it was opened once it was never the same again.”
According to many designers, the most common fault is poor installation. “There’s such a huge potential for error in sweet success the toffee Factory in
Newcastle upon tyne features extensive use of in-ground lighting. it has withstood flooding and still works as it should a few years after opening installation,” agrees Simon Fisher, director at F Mark. “Ninetynine per cent of the issues I have experienced on site have been around installation as opposed to the integrity of the fitting.”
These problems include inadequate drainage and fixings not being properly tightened. Water can also be sucked in at the base when pressure drops inside the fitting as it cools down after use. But, despite the problems, the aesthetic effect is undoubted:
“Whatever you say about in-ground luminaires, the effect is stunning,” says Fisher.
Installing confidence
By taking a close look at in-ground lighting schemes that have been successfully installed and stood the test of time, it is possible to draw on some common design guidelines and practices that help overcome the barriers often encountered. Of course nothing stays in a perfect state forever, but neither does anyone want their work to look like our “hall of horrors” (pictured, page 30).
With installation cited as the main problem, building up a good working relationship with the contractor is key to the www.lighting.co.uk
February 2014

 ProducT anaTomy Artemide’s
Algoritmo linear fitting p32
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The inTegraTion issue solution. Anthony Smith, a director at Stainton Lighting Design
Services, used in-ground extensively at the Toffee Factory in
Newcastle upon Tyne. Built on a flood plain, it has flooded twice since the lighting’s installation 18 months ago – it could be a disaster story but instead still works properly.
Stainton started off by sitting down with the contractors, explaining what they were trying to achieve overall and getting any input about how the project could be improved.
They then had a big on-site presence during installation.
“We oversaw the installation process, attended on-site meetings with the contractor, drove what happened, made sure the install was right and that the contractors followed the methodology in place. We also wrote a fairly comprehensive specification,” says Smith. “Engagement is a really big thing.”
Watertight success
Rory Marples, design and technology manager at iGuzzini said there should be opportunities for manufacturers to talk directly to installers to help overcome problems. “The manufacturer is best placed to speak to the installer and help avoid the most common pitfalls,” he says.
Of those pitfalls, water ingress is certainly the most common.
The advent of LED in-ground luminaires means there’s no longer the need to open the fitting for lamps to be installed.
Sealed fittings also help avoid mould growing inside. LEDs still heat up, but less so, and are manufactured to mitigate this. Manufacturers acknowledge installation issues and try to overcome them – iGuzzini fits a “pull and transpiration prevention device” that helps prevent the capillary action within a cable where moisture is drawn through the cable into the luminaire housing. In addition, some products have a separate compartment to isolate the electrical components and optical assembly from any moisture ingress associated with the incoming cable.
Fittings must also be installed in the right setting and with adequate drainage. Smith recommends an area with a high footfall to avoid vandalism but there’s still an issue regarding moisture. An IP rating may specify that a fitting can be temporarily submerged, but it isn’t designed to be submerged in a puddle for 24 hours. When Mark Ridler designed his celebrated scheme at Finsbury Avenue Square in London (see next page), the luminaires were tested to meet IP 66, 67 and 68 and a mock-up was placed in situ for four months of testing before the design was given the go-ahead.
“It was tested to within an inch of its life,” says Ridler. And to complement the rigorous testing the land owners and manufacturers put a post-installation maintenance programme in place.
Made to measure
Many of the in-ground designs that have stood the test of time have used bespoke fittings or had elements specifically designed to suit the individual setting. Stainton’s design around Durham
Castle featured a UV-stable polycarbonate cover over the luminaire to protect the original glass from damage caused 
To protect and serve At Durham Castle a UV stable polycarbonate cover was used over the luminaire to protect the original glass from damage (above)
The eyes have it Despite the problems, many designers agree that the impact of in-ground lighting can be stunning, as in this design by Dean Skira at The Park at Villa Colloredo Mels, Recanati, Italy www.lighting.co.uk
February 2014

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The inTegraTion issue
ground-recessed luminaires are notoriously problematic. We take a look at some of the most common pitfalls.
1 the Finsbury Avenue square installation has stood the test of time; a decade after installation, it is an exemplar of in-ground design
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February 2014
Mouldier than a piece of stilton left over from
Christmas, the impact of this luminaire is severely impinged by a nasty-looking green coating that has built up inside
perfectly horizontal is the ideal setting for an in-ground luminaire, but this one is beginning to dislodge the problems above can affect the amount of light the luminaire emits, if it works at all
Crosses to bear the metal channel intersections at
Finsbury Avenue square, london, have withstood a decade of heavy footfall by debris from nearby student accommodation. Smith says this only reduced the light output by 5–10 per cent, with no discernible effect to the lighting optical control.
At the Toffee Factory bespoke housings for the Urbis Noctis
225s fittings were built. Smith says: “We used Gell joints for all underground terminations and they work really well. If you get a luminaire that’s damaged, you can easily lift it out. You’ve effectively got a waterproof connection you can replace easily.”
At Finsbury Avenue Square, Ridler and the team at Maurice
Brill Lighting Design (with whom he was working at the time) worked with Artistic Licence to design the critical detailing of the metal channel intersections. They paid great attention to how the luminaires sat in the ground, in addition to gasketing, adhesive and glass specification.
A new light
The Finsbury Avenue Square scheme was designed just over ten years ago and, today, many luminaires have technology that overcomes historic problems. Paul Davidson, business development manager at Aurora, said he understands why there has been caution but argues that, when specified correctly, technology is also improving the overall quality of light.
“Previously in-ground LED luminaires would light up but not produce any illumination. Only in the last year or so have they been at a good enough level of performance that they’re acceptable for this sort of commercial application.”
LED technology now also offers other benefits: it allows the luminaires to be different shapes, rather than the standard linear or circular form factors dictated by older technologies; optical control can be greater; and the heat is reduced such that the depth of the luminaire can also be reduced. Previously, the use of discharge sources required fairly deep housings to accommodate a reflector large enough to ensure a suitable degree of efficiency and reduce surface temperatures.
The new year’s heavy rainfall will have certainly tested in-ground lighting designs, and problems can obviously been seen in some. But by using the latest products and know-how, maybe it is time to see in-ground luminaires in a new light. n www.lighting.co.uk