Design Clinic started in a small office two years ago and now we are in the prestigious entrance hall of LuxBank – ‘We illuminate your finances and lighten your debt’.
This month, we are lighting the entrance hall.
Visiting several banks recently, I’ve been surprised by how similar they looked. They all had high ceilings and most had a vault or raised section for daylight – or the appearance of daylight. The architectural style is open plan and friendly.
Gone are the days when staff sat behind inch-thick bullet-proof glass partitions. Shotguns are just sooo pre-internet. The banks I visited were full of visible cameras and I suspect there were a lot more unseen ones.
Light sources can cause flare and close a camera’s automatic iris, darkening the image. This can be avoided by ensuring that the luminaires are above the sight-line of the cameras.
Although banks appear open plan, there are limited ways in which you can walk around. Fore example, you are unlikely to get a view from behind a staff desk. You can design your lighting accordingly.
There’s not much guidance specifically for banks except that most public areas should be lit to 300 lx. Obviously, your lighting design should match the image of the bank.
My three designs are the first for a long time that do not use LEDs – for no particular reason.
Our bank lobby is about 10 x 10m with a 3.75m-high ceiling.
Youy must put plenty of light on high-vaulted ceilings to show off the architecture and bring out the volume of the space.
Inevitably, this will require some upward light. A simple way is to use a prismed glass bowl. These bowls can direct a fair amount of light downwards. Being transparent, they are not as imposing as a solid steel or aluminium luminaire. A halfway house is to use opal diffusers. These can give a softer appearance but don’t control the light so well.
The units have 55W twin-limb compact fluorescent lamps. The complete luminaire delivers over 70 lm/W so it easily meets Part L. It can be dimmed and controlled to suit those who prefer Leni calculations and have daylight to harvest.
The vertical lamp and glass bowl ensures good vertical illumination. Similarly, the large area of the CFL lamp means no strong shadows.
Luminaires Compact fluorescent pendant
Optical control Prismed glass
Arrangement 3 x 3 over main area
Average horizontal illuminance on floor 380 lx
Electrical load 5W/m2
Pros Well-lit appearance and low installed load
Cons Needs interesting architecture so it’s not confused with a DIY warehouse
Gimbal luminaires are much beloved by lighting designers because of their flexibility. They can also pack a punch and deliver contrast. Gimbals are usually offered with two, three or four aimable spotlights. In turn, these can have narrow, medium or wide beams. These luminaires are great if the layout of the furniture and counters is likely to change.
I have combined a wide beam for general lighting and a spot to highlight the walls and add some contrast. These units use 35W metal halide lamps in an engineered reflector. You can easily achieve 1,000 lx 3m away with the spot.
One disadvantage of these gimbal units is that their aim is often dislodged during cleaning and relamping.
Again, you can get LED equivalents of these 35W lamps and these, to some extent, overcome frequent relamping and mis-aiming problems. However, you do pay a premium.
Luminaires Twin lamp gimbal with 35W metal halide
Optical control Facetted, aluminium reflector
Arrangement 3 x 3 twin lamp units over main area
Average horizontal illuminance on floor 430 lx, varies with aiming
Electrical load 7W/m2
Pros Lots of flexibility in terms of appearance
Cons Not so good for vertical illumination; could be glaring if not aimed properly
Uplighters can provide a brilliant solution, but because the light is reflected off the ceiling before it enters the space, there are some losses in efficiency compared with downlights.
However, if your ceiling is embellished or decorated, why not highlight it?
The big advantage of uplighters is that is that the space looks light and airy. This option provides the highest average vertical illumination on the walls. It also puts the most light on the tellers’ desks. Part of the lighting design is to specify a high-reflectance paint finish for the ceiling.
The four pillars are ideal for mounting the uplighters. Having an uplighter on each face improves symmetry, but you could save energy by omitting the units that light less important areas. Uplighters are above the CCTV cameras to avoid lens flare. Being on a pillar simplifies maintenance.
Luminaires Wall-mounted uplighters with 70W metal halide sources
Optical control Reflector and lens
Arrangement Four on each pillar
Average horizontal illuminance on floor 395 lx.
Electrical load 12W/m2
Pros Plenty of light on the ceiling.
Cons Can seem too diffuse unless you also add some highlighting