This Design Clinic is more about lighting techniques than alternative ways to light a space. The retail sector is a hugely important part of any economy and, as a result, it has its own supporting services sector, of which lighting design consultancy forms an important part. It’s not an exaggeration to say that the UK is a world leader in retail lighting design.
Rather than being a ‘beginner’s guide to retail lighting design’, this clinic is about techniques that can be applied to all types of display lighting. To generalise, regardless of the application, the brighter the average illumination and more uniform the lighting, the less ‘exclusive’ is the brand image. Think of the lighting in a burger chain compared with a small, expensive restaurant. Similarly, compare the lighting in standard and first class railway carriages.
Retail lighting is much more varied than that in other sectors, so guidance can only be given in the most general terms.
When a solution can’t be found in one of the lighting guides, a useful approach is the technique of layering, where the overall design is built up by considering the different uses of the lighting.
For example, you need to provide enough light for public safety in circulation areas, and when lighting steps and changes of level.
Another ‘layer’, and the one that involves most design skill and effort ,is lighting the products on sale. It can be argued that this is the most important aspect of retail lighting, because if no-one is attracted into your shop, the rest is wasted effort.
Don’t forget functionally important areas such as the payment desk and ‘returned goods’ section.
Our three options demonstrate a simplified version of this technique. The views shown measure about 8 by 12m and the ceiling is 3.5m high.
Panel lighting in all its guises is a very popular way to provide good, overall illumination in a retail space. It’s great in terms of watts per square metre, you can easily obtain high CRI versions, and the colour temperature is the same everywhere so there’s no need to wander around checking what the merchandise looks like. If you want energy-efficient, uniform, functional lighting, this is it. The only decision you have to make is the lux level you want.
This notional design achieves a horizontal illuminance of about 400 lx and almost the same on the walls. It could easily be much brighter and achieve 800 lx simply by doubling the number of panels. As with all flat panel schemes, the ceiling is a bit dark. This is a bugbear of mine but most people don’t notice.
What this scheme doesn’t do is excite the shopper. It’s easy and efficient, but you are unlikely to linger.
- Luminaires 600 x 600 LED panels
- Optical control Opal diffusers
- Arrangement 4 x 3 in central area
- Average horizontal illuminance 400 lx
- Electrical load 8W/m2
- Pros Economical
- Cons Doesn’t excite
This is the opposite extreme to the first scheme, and uses narrow-angle 15-degree track spotlights and medium beam gimbal fittings. Although the average horizontal illumination is only slightly less, the effect is dramatically different. Obviously, the illumination on the vertical surfaces is much higher than in scheme 1. Don’t mention uniformity.
The gimbals provide some background illumination but the impact comes from the narrow angle spotlights focused on the objects on display. It’s a much more dramatic and interesting scheme. All the spotlights can be aimed, so it is much more flexible and can be adapted as the store layout changes.
Of course, this option also has disadvantages. On a practical level, you need to make sure the spotlights are aimed correctly. Missing the merchandise might also mean unnecessary glare for customers. Spotlights with a locking mechanism go a long way to overcoming this problem.
Unsurprisingly, the electrical load is much higher than that of the first scheme.
- Luminaires Spotlights in a recessed track plus twin gimbal units
- Optical control Narrow-angle reflectors
- Arrangement Can easily be varied to suit the merchandise
- Average horizontal illuminance 360 lx
- Electrical load 13W/m2
- Pros A lot more exciting than option A
- Cons Watch the aiming
This combines features from the two options above. We still retain the flexibility of scheme 2 by using some of the track spotlights, but the wide-angle gimbal units have been replaced by far fewer panels. This may not please everyone because although the ceiling is less cluttered, many prefer the look of a gimbal to an opal diffuser ceiling panel.
We could also have reduced the number of spotlights further. It’s an example of where you need to match the design to the store architecture and what will be displayed.
The advantage of this scheme is that there is a degree of highlighting on the merchandise and the lighting can be adjusted to suit a changing store layout.
One aspect to watch out for is the colour temperature of the luminaires. Some shops go for cool background lighting and warmer spotlighting.
The Lux team went to one store where, everyone agreed, there was too great a difference between the two and your eyes had to constantly adjust depending on where you were looking.
- Luminaires Opal panels plus narrow spotlights
- Optical control Diffuser and reflector
- Arrangement As shown but can be varied
- Average horizontal illuminance 385 lx
- Electrical load 10W/m2
- Pros A good mixture of background and spot lighting
- Cons You still have to watch the aiming