HOW TO...
How to… light a home to Part L

Creating great residential spaces has just become a lot trickier – thanks to a more onerous Part L. So we’ve asked top designers for the 10 best workarounds – so you tick all the right boxes while keeping the wow factor. Jill Entwistle reports

Talk to a lighting designer only a few years ago and he or she would have had serious reservations about substituting incandescent lamps with certain low energy sources in a domestic setting. But improving technology, adaptation of techniques and the sheer relentlessness of legislation has made it less of a distress decision and more of an opportunity for creativity.

‘Given the huge range of colour temperatures available in fluorescent lamps, and the improvements in LED sources, I truly believe that all but the most traditional of buildings can actually use energy efficient light sources to their advantage,’ says Max von Barnholt of VBK Lighting.

An indication of the change, says von Barnholt, is a project he’s had on the drawing board since 2006. ‘Since then we have been able to review the scheme so that now we do not have a single incandescent specified. I would not have been comfortable promising that to a client back in 2006, but stability and diversity is such now that it really is viable.’ (As he points out though, the budget has doubled. LEDs remain costly and dimmable fluorescent control gear doesn’t come cheap.)

While the holy grail of energy efficient sources, from compact fluorescent to LEDs has been the light quality and colour temperature of halogen – with varying and evolving degrees of success – these are different beasts and need a different approach to conventional lamps. And while linear fluorescent is easily dimmable and LEDs were born for it, it is still an issue with CFLs. In most cases, in other words, simply retrofitting will not do.

1 CONCEAL where you can

Low energy sources can actually add glamour to bedrooms with some forethought, says Sally Storey. If the headboard is slightly built out from the wall, for instance, then dimmable fluorescent or RGB LEDs can be hidden behind to create either white light or colour effects. ‘The key is using the light source totally concealed to rely on the reflected light,’ says Storey. ‘Another technique would be using recessed fluorescent or LEDs to uplight sheers.’ Obviously the technique also translates elsewhere.

2 EXPLOIT THE 1W LED

For steps, plinths, niches, low voltage fittings can be replaced with 1W LED fixtures. ‘Within Part L, the 1W fixture either doesn’t even count as its wattage is so low – fixtures of less than five circuit watts are excluded from the total luminaire count – or limited in groups of five with a dimmer to count as one circuit watt,’ says Sally Storey of LDI. ‘Linking them together may be important if you want to introduce a less energy efficient fixture.’

3 INTEGRATE where you can

For a London residence, Firefly Lighting Design had to design not just to Part L, but to the BREEAM standard, where 75 per cent of all installed fittings had to be energy efficient. Integration was the key. ‘We worked with the architect to design lines of light integrated into architectural features such as the stairs,’ says Peter Veale. ‘This allowed us to create some breathtaking effects while allowing the clients energy leeway to choose their own bedside lights and pendants.’

4 USE DISPLAY DETAILS

‘Lighting shelves or niches can be about maximum effect with minimum energy,’ says Sally Storey. Here niches are backlit with LED strip (400 lumens output at over 45lm/W). A dimmer ensures the correct lumen wattage per circuit watt. In front a small footlight with a 1W chip (see above) focuses on each object. In a meditation room designed by VBK Lighting, the niches are the sole light source, in this case using fibre optics (250W HID projector with 30 tails).

5 PLAY TO THEIR STRENGTHS

Rather than viewing low energy sources as a substitute, look at how their specific characteristics can work to advantage in some applications. Linear LEDs were ideal for this shower, for instance, because of their compact size, longevity and option of cool white colour temperature. ‘The cooler output gave a more vibrant feel to the blue mosaic,’ says Peter Veale, ‘while the long life allowed us to consider the installation as permanent, which would not have been feasible with low voltage.’

6 LAYER the light

Layering is a general lighting technique and energy efficient sources particularly benefit from the more dramatic effect it creates (discharge sources such as fluorescent used alone can produce a flat effect). In this kitchen by LDI using John Cullen Lighting fittings, 1W LED fixtures (see above) are used at low level in the kick-plinth. CFLs work well as wall lights and work units can be made to float using linear LED products above and below creating both task and uplight.

7 PICK YOUR LOCATION FOR HALOGEN

‘Do it in the kitchen, in the hall, on the stairs and in the bathroom, but keep it out of the bedroom and the lounge where you want a more relaxing atmosphere,’ says Douglas James of Mindseye. ‘Dimmable halogen is the best way to get really low light levels, and still get the best quality light. It’s a matter of using it sparingly and judiciously.’ If you are going to do it in the bedroom, use techniques such as concealment…

8 MIMIC DAYLIGHT

Relating to the point above, unlike warm incandescent sources, cool white LEDs and fluorescent can be used to introduce a sense of daylight, using a mock skylight, in basements and other windowless places. For instance dimmable fluorescents in different colour temperatures (2800K and 3500K) within a Barrisol frame allow variable mood and time-of-day effects. Mindseye created a similar effect in a basement gym and swimming pool, above, also with dimmable T5s and Barrisol diffuser.

9 USE DIFFUSION AND REFLECTION

Related to concealing the fitting is diffusion and reflection, mellowing potentially harsh effects. ‘Try to ensure the light is delivered through some form of diffuser, or as reflected, or indirect, light – for example, bounced from a wall or ceiling,’ says Douglas James. ‘Both options will soften the light and create a more appealing atmosphere.’ In this case, a continuous T5 fluorescent detail cuts through three storeys, underlining the verticality of the space and lending a gentle glow to the stairwell.

10 TRADE OFF WHERE YOU CAN

Appropriate use of low energy means the odd incandescent can be dropped in, balancing the effect and the efficiency. Here five 1W LED uplights with 10-degree beams create shafts of light behind the bath. Linked on one driver, they again act as one energy efficient unit (see 1W LEDs above). ‘Balancing the use of a narrow-beam 35W low voltage halogen downlight, Part L-compliance is achieved by using fluorescent (warm white) for the backlit, frosted elements of the mirror,’ says Storey.

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