Before You Buy Another Lightbulb, Read This — It Might Just Change How You Light Your Entire Home

Have you ever read the description of a light bulb and started to feel as though you're reading an unknown language? Honestly, sometimes I feel as though I'd have better luck understanding hieroglyphics; at least there are fewer random letters jumbled together on the walls of the caves.

I may sound as though I'm being hyperbolic, but terms like CRI and Lumen trigger the same reaction in me as an algebraic fraction - pure fear. However, unlike an algebraic fraction, understanding all this lightbulb lingo would actually be a real help in my life when planning my home lighting scheme. You see, there's nothing I hate more than the harsh, bright illumination you get from many overhead lights, and if I can do anything to ensure I never have to subject myself to that again, I will.

And so, with that in mind, I set out to fully decode the mystery that is our lightbulbs. With plenty of help and assistance from the experts, of course. Now, I've compiled all their knowledge, so we can all have one comprehensive guide to buying the right bulbs. You're welcome.

What Does Wattage Mean?

So, let's get started with the basics: what exactly is wattage? Well, simply put, "Wattage is a measure of electrical power used by a product," explains Hazel Park, lead lighting designer at John Cullen Lighting.

That means the higher the wattage, the more electrical power the bulb requires, which directly translates to the energy efficiency of the light, so opting for a lower wattage bulb is a smart design choice to help save on bills.

"Halogen lamps (made of halogen gas and a tungsten filament) consume 20-40 watts and are much less energy-efficient than modern alternatives like LEDs," says Hazel. "LED lamps consume closer to 7-10 watts, have a longer lifespan, and are widely used across households since the Government changed Part L building regulations in 2021."

In most cases, a lower wattage bulb will be the more desirable option, for both environmental and cost reasons, though knowing how long LED lights last will also help you to plan more effectively.

While you may assume the amount of power would have a direct correlation to the intensity of light, this is not the case. "Wattage is simply the amount of power a bulb uses, not the quality of light it gives," explains lighting designer Alvaro Picardo. "People often chase high wattage thinking it means brightness, but what you really want is control. I always look for bulbs that give good light with minimal energy; it keeps the atmosphere soft rather than flattening a room with unnecessary intensity."

What Does Lumen Mean?

While wattage measures the amount of power the light consumes, it doesn't necessarily reflect the light itself. Instead, this is measured by something called a lumen. "Lumens measure how much light a fixture emits," says Hazel. "The higher the lumen count, the brighter the light appears."

Although lumens measure light brightness, the amount of light that illuminates other objects is measured by something else entirely (confusing, I know). As Hazel explains, "It’s lux (light that reaches a surface) that determines how bright something appears."

So, lumens is a measure of the total amount of light a bulb emits, while lux measures the amount of light that will fall directly onto a surface. But either way, to make your overhead lighting less harsh, you'll want to look for a lower lumens and lux number.

"In commercial settings, regulations on lux level ensure consistent, even illumination, whereas residential lighting offers more creative freedom to play with shadow," says Hazel. "For example, while a table may require 300-500 lux to evenly light a dining room tabletop in a commercial project, a home can achieve a striking effect with just two downlights accenting with narrow beams onto a centrepiece. By thoughtfully positioning lighting and layering different types of fixtures, you can introduce drama, depth, and beautiful contrast." So, by combining plastered-in ceiling lights for subtle overhead lighting with wall lights and floor lamps, you can create a richer, layered look.

Don't be fooled into thinking the higher the lumens, the better. "In most homes, you want layers rather than a single dominant source, table lights, wall lights, and shaded lights. Lumens should match the purpose of the space, not fight it," says Alvaro, "A room only feels balanced when the brightness sits comfortably within it."

What Type of Bulb Is the Most Energy Efficient?

As we've already established, the energy efficiency of your lights will directly correlate with the wattage of your bulb.

Old-fashioned, or traditional light bulbs, like incandescent lamps, are typically less energy-efficient options, while more modern LED lighting tends to use less energy. Hazel explains the mechanism behind this, saying, "An incandescent lamp is made up of a metal filament and a gas. When the thin wire filament is heated, it glows to produce light. These lamps release mainly heat and are not very energy efficient. The light quality is beautiful with an excellent CRI. On full brightness, they produce a clean white light, and when dimmed, they turn orange like a flame."

Although they aren't the best in terms of energy efficiency, many people will still opt for incandescent lights based on the warm, cozy glow they are able to emit, a contrast to the manufactured effect from LED lights, a type of lighting you may want to avoid if you want your home to feel cozy.

LED, Hazel explains, stands for light-emitting diode, and is "a blue semiconductor LED chip coated in a thin layer of yellow phosphor to convert it into a yellow/white light." She continues, "Little energy is wasted as they produce far less heat, making them a much more energy-efficient choice."

Another reason many people opt for LEDs nowadays is due to the amount of control they're able to have over their appearance. So long as you make sure you're buying the right ones. "Most LEDS have a set color temperature and come in varying ranges of CRI. Therefore, it is key to study the detailed information to select a high-quality lamp for a home," says Hazel.

She further explains that, "Dim-to-warm LEDs have a mixture of different coloured yellow chips in one product. These can be dimmed individually to create a color shift when dimmed, similar to an incandescent bulb. RGB LEDs are also available for bright color solutions. These are perfect if a client wants to inject a bit of fun into a media room."

In summary, Alonso explains, "Incandescent bulbs have a warmth that many people still love, the color is familiar, almost nostalgic, but they use a lot of energy and don’t last long. LEDs are vastly more efficient and now come in tones that are much softer than earlier versions. I choose LEDs for almost everything; they respect both the room and the planet. The key is selecting the right color temperature so the light stays humane."

What Does Light Temperature Mean?

"Light temperature relates to the color of the light and is measured in kelvins. The higher the kelvins, the cooler or whiter/sharper the light color. The lower the kelvins, the warmer the light color," says Hazel. "Halogens would change color when you dim them, so when they are on full brightness, they were a high kelvin, then when you dimmed them, they became warm and orange like a flame."

The best lighting measurements will change based on the environment in which you plan to use them, and thinking about how cool vs warm light will look in that space. "In residential properties, we advise 2700k (kelvins) for LED downlights and 2400k-2700k for LED strips and lamps for decorative fixtures so it feels cosy and inviting," says Hazel.

Generally, 2400k to 2700k is the range within which the experts recommend you select for your lighting. "When choosing between 2400k and 2700k, the colors and textures in the space should be considered as well as the mood you want to create," For example, when choosing in cabinet lighting, "A shelving unit with cool blue paint colours may benefit from 2700k for a 'fresh' feel, whereas a warm oak finish may benefit from a 2400k, which has more red tones in it."

What Is CRI?

One term that will come up a lot when researching lighting is CRI, meaning the color rendering index. CRI is a measurement of the light's spectrum, and will be anywhere between 0 to 100, with 100 being the highest possible, and reserved solely for lights with the same spectrum as daylight itself. It will affect the way colors appear in your home, and it explains how lighting affects paint colors.

"CRI (Color Rendering Index) is a measure of how accurately a light source reveals the true colors of objects," explains Hazel. "High CRI enhances visual comfort and renders paints, fabric, and natural materials to their truest colors. Look for a high CRI of 90 or more to ensure that your colors are true rather than insipid."

This will be especially significant in rooms like kitchens and bathrooms, where accurate lighting is essential.

The Best Bulbs for Every Room In Your Home

"Maintaining a consistent color temperature in downlights throughout different rooms is essential for creating a cohesive and harmonious lighting scheme as you move through a building," recommends Hazel.

Instead of switching it up from room to room, she suggests, "A warm 2700k is recommended, paired with a high CRI of 95+ to ensure artwork and materials are rendered to their truest tones, enhancing a warm and inviting atmosphere. Lamps should be fitted in a fixture that has a baffle to reduce glare, making them as discreet as possible to keep the focus on the interiors."

Alonso, however, takes a different approach: For your kitchen lighting, he says, “You need clarity without glare. A warm LED with slightly higher lumens works best, with enough precision to cook, but without tipping into harshness. I would use a few well-placed spotlights below the cupboards, directed over the counter to give light and clarity to the work surface. Add a couple of lampshades to bring warmth and a sense of comfort; the kitchen today is the heart of the home."

In the bathroom, he says it benefits from gentle, even light. "Avoid anything too cold; it makes the space feel superficial. A soft, warm LED turns the bathroom into a place to restore, not rush. One wall light for the bathroom mirror, a general ceiling light, and a considered light over the shower will create that balance."

The living room, Alonso argues, "is where layered light matters most. Use lower-lumen LEDs in shaded lamps to create structure and intimacy. The goal is not brightness, it’s balance. Lampshades must sit at eye level, no higher, and you include a couple of reading lights positioned beside comfortable armchairs."

And finally, when it comes to the bedroom lighting, Alonso says: "Always warm, always low. Bedrooms should allow the eyes to relax. A shaded lamp with a soft LED creates a calm, steady envelope of light.” Add a small reading lamp on each side of the bed so you can read comfortably at night.

Now you know all the lingo, you're all set to go out and get involved in the hottest lighting trends for this year, and may as well impress everyone with your new knowledge, while you're at it.