Lighting guide for a 30′ × 40′ shop.

Lighting guide for a 30′ × 40′ shop.

Illuminating a retail area is different from illuminating a residential space. Factors like sufficient light, contrast, shadows, glare are required to be addressed professionally. In this guide, all the factors of lighting a 30’×40′ shop are briefly explained in a simplified way.

how much light is required in a 30′ × 40′ shop

The publishing of Helwan University (interior design) recommends 65 lumens per square foot to properly illuminate visually demanding indoor spaces like a shop. This means that for a 30′ × 40′ (1200 sq. foot) the recommended brightness is 78000 lumens.

knowing the recommended lumens for 1 square foot of a shop the lighting requirement of any shop can be calculated.

How to install lights

Professionally, lighting in a retail area is installed in such a way that it illuminates both the products as well as the background (walls) such that the illumination of the products is not less than 1/3 of the illumination of the walls.

simply put, the walls should not appear dull in contrast to products and vice versa.

Lighting both walls as well as the products is important in a retail space. As cited by lighting experts

Good wall lighting helps people get their bearings in the room. It can also make a room look more livelier

Sara Mohamed (Master 2010/2011) – Helwan university


Install lights on the ceiling of shop.

lighting must be installed in a way such that walls are showered with light as well as the product shelves also appear illuminated.


Install lights 12 – 14 inches away from the corner of the ceiling to illuminate the walls throughout. Led tube lights facing downwards are an excellent way to illuminate the walls.

The height at which lighting is installed varies with the height of ceiling. A good rule of thumb is to place lighting between 8 to 10 feet height maximum. This will ensure there is no loss of brightness as well as even distribution of light.

How far apart to place lighting depends upon 3 factors.

  • The brightness of the source.
  • Height of the ceiling.
  • Length of room.

Ideally, light fixtures up to 3000 lumens can be kept 2.5 feet apart for proper distribution of light over the wall.

Other lighting options to illuminate walls.


Both of them are LEDs but there two major disadvantage of using recessed lights over led tube.

  1. The brightest of recessed lights (6 inch recessed lights) gives around 1000 lumens which is very less compared to 3000 lumens of Led tube lights.
  2. Most part of the recessed light needs to be installed inside the ceiling which may require creating holes within the ceiling. Thus, increasing the cost of installation.

Track lighting also is low in brightness as compared to LED tube. A 4 feet track rail can install 4 track light units. Generally, each light unit emits 500 lumens . 4 × 500 = 2000 lumens which is less compared to 3000 lumens from a LED tube light


Adding more than 4 bulbs can focus all the light to a particular spot and hence create unwanted glares. A similar size 4 feet led tube emits light that distributes evenly on the wall.


Products require lighting from two sources. The first source of light illuminates the product and walking area while other source illuminates their immediate background (shelf cabinets)

Install lighting between two adjacent product shelves at a height of 8 feet to 10 feet maximum. For low ceilings 8 to 12 feet ceilings install lights at a height of 8 feet such that the products placed on both the shelves are illuminated as well the walking space between them is also illuminated as illustrated in the image below.

For very high ceilings >14 feet prefer to install lights at 10 feet height.

The ceiling lighting must be installed at 90 degrees to the floor to avoid unwanted glare and shadows.

The light from the ceiling not only illuminates the walking areas but the products as well. This practice drastically improves the look of a store.



To illuminate products within shelves accent lights like led under cabinet lights is an excellent choice. These LEDs are in a small tubular shape emitting around 1200 lumens while being highly power efficient (uses only around 12 watts).

However, if the product shelves are small and congested in space a much more easy method is to simply stick a led light strip within the shelf. These are very small LEDs hence not take any space.

Their brightness is also less compared to undercabinate lights but using sticking multiple LED strips can make a dark looking shelf bright.

Color Temperature of lights in a 30′ × 40′ shop

Along with the design, placement, the color temperature of lights in retail spaces is also an important factor to consider as also pointed out by lighting experts.

The study of lighting has important implications for consumer behavior and is an important aspect of consideration for the retail industry.

Dalal Anwar Alsharhan – Arizona state university.

Experts from illuminating engineering society cite that cool lights 7000k – 7500k are more suitable in warm areas while warm white lights with temperature 2700k – 3000k are preferred by customers in cold areas. Men and women perceive color temperature slightly differently.

Stores that are related to clothing should have a color temperature of 4000k – 4800k for accurate perception of colors. This spectrum of color temperature falls in natural daylight category and is suitable for precise color perception.

Stores which are related to food and dinning for eg. restaurants should have lights within warm white temperature (2700k – 3000k)

For grocery stores 5000K – 6000K natural white temperature will make things easier for the consumers to read product descriptions as well spot particular product.

How to save cost on lighting a shop

High brightness is required in a shop thus choosing the right type of lighting is also important. There are three types of lights LEDs, fluorescent and incandescent.

(assuming running 20 hours / day)
Average working expectancy.
LED15000 lumens150 watts11.87 $50,000 hours
FLOURESCENT1000 lumens
( means 15 individual units × 1000 = 15000 )
14 watts
(14×15 = 210 watts total)
16.62 $20,000 hours
(200 × 600 individual units = 15000 lumens)
25 watts
(25 × 600 = 15000 watts)
1,187 $3000 hours

We compared the highly bright LED lighting type LED Garage lights with fluorescent lights and incandescent lights.

From the above data it is clear that LED lighting absolutely dominates fluorescent and incandescent lighting source in terms of performance, running time as well as energy efficiency.

A single LED garage light can emit up to 15000 lumens with much less wattage which if tried to accomplish by fluorescent light can take 15 individual units. Thus LEDs both save space as well as energy.

LED lights are an excellent choice to illuminate product shelves and walking areas while LED tube lights can be used to illuminate the walls.


When we are indoor like in a room naturally, our gaze constantly switches from near objects to far objects (walls). If the difference in brightness between near objects and far objects is substantial our eyes need to adapt constantly.

This makes them tired very quickly which affects the visual performance of customers and can ultimately impact their shopping behaviour as well.

Thus, it becomes the first priority for shop owners to get the lighting done professionally.

Below are the factors which a professional lighting designer considers while lighting a commercial area like a shop.


The luminance (light reflection from an object) of products placed on shelves should not be less than 1/3 of the luminance of the walls behind. This will keep the eyes of customers in focus without feeling a constant need to readapt. Thus improving visual performance.

For example, if the walls and products are illuminated with a same light source of 3000 lumens then that light source should be placed such that the products should not appear dim in contrast to the wall i.e. product should have a minimum illumination of 1000 lumens or more.

First illuminate walls and all the dark corners then, lessen the difference in brightness between products and walls. Bright walls can make a room look more alive.

lighting influences and creates excitement in the store

Wharton School of Business, 2010, Cited at DiLaura, Houser, Mistric, Steffy, 2011: P.34.1

Glare reduction

Glare is one of the major side effects of improper placement of lighting. Glare not only arises by reflection but also via marked differences in contrast between bright and dark areas.

Glare from glass products can be easily avoided by placing lights on the ceiling at an angle of 90 degrees to the floor.

The practice of illuminating the immediate background of products also aids in minimizing unwanted glares.

These simple practices can drastically improve the ambiance of a shop.

countering Shadows

This aspect of professional lighting is fairly simple and can be overcome by readjusting the physical objects within shop. To avoid unwanted shadows lighting must point downwards making an angle of 90 degrees with the floor.

How to check if there is enough brightness in the shop

To precisely check the brightness of any indoor area can be measured by using a lux meter. With the help of a light sensor, this device measures the intensity of light falling on it and provides a reading.

If lux meter is not available then all the lighting products have their lumen output printed in their description. Adding all the mentioned values, a fair idea of total illumination can be obtained.


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