How to Install Downlights in Your Ceiling (2023)

Having spot lights recessed into your ceiling is a fantastic way to light a room, especially where it is not practical to have other types of lighting, such as a pendant light. Pendant lights are not as effective, particularly in bathrooms or kitchens. Fitting downlights is a job that you can do yourself, however like any electrical DIY project if you are not totally sure about what you are doing them you should get a professional electrician to assist you.

For more information about electrical safety and what you are and are not allowed to do yourself, please see our project on Part P of the Building regulations.

Now we’ve got the important safety information out the way, let’s get on with fitting some downlights.

Fitting Down Light Spots

There are really only 4 steps to fitting ceiling spots:

1. Positioning the downlights
2. Fitting the downlights into ceiling
3. Wiring the lights
4. Inserting the down light unit.

If you are simply replacing your spots with something a little more modern or are up grading to LED lighting then you can jump straight to the 3 stage, as stage 1 and 2 will have already been done.

We explain more at the end of this project about the types of light bulb or lamp you can choose including the benefits of moving to LED and the impact this might have.

1 – Positioning Ceiling Spotlights for Installation

Before you even start your project you do need to confirm that fitting downlighters is not going to compromise fire safety and the building regulations; the ceiling will slow the spread of a fire but it will not be as effective if it is peppered with holes for downlights. There are fire rated downlights which should be use in these situations, and we suggest should always be used for safety’s sake.

Positioning your spotlights is something that needs some careful consideration. In a kitchen they should be positioned over the worktop so that they don’t cast a shadow when you’re preparing food; typically unity will be 600mm wide so you should keep within this distance from the wall ideally.

The number of lights needed will depend on the brightness of the lamp or bulb and what you are going to use the space for. In a kitchen you’ll need brighter lighting than in a living room and a good measure for the brightness can be approximated by using Watts or “equivalent Watts” if you are planning to use LED bulbs.

It is typical to have the spots spaced at between 1.2 m (4ft) and 1.5 m (5ft) but this is entirely up to you, and people tend to suggest it is better to have more rather than less, as you can zone the lighting with switches or have a dimmer switch to tone it down if necessary.

A handy way to approximate how many downlights you will need is using this method:

1. Calculate the room area (length X width) in feet – eg, 8ft X 15ft = 120 ft2
2. Multiply by a lighting factor – 1.5 for a living room or 2.5 for an area which needs more light like a kitchen for example – eg, 120 ft2 X 1.5 = 180 Watts
3. Divide the Watts needed to light the room you have calculated by equivalent Wattage of the bulbs that you’ll be using to give the number of bulbs you will need – eg, 180 Watts ÷ 35 Watts = 5.1. Therefore you will need between 5 & 6 recessed lights

But, of course, it is entirely up to you how many you have!

The big thing to watch out for is where the joist or any other obstructions might be. If you cannot get access from above, either from the loft or by lifting the floor boards, use a stud detector to do this and also to see if there are any pipes or cables that are going to cause you problems. Joists will be (should be!) evenly spaced so once you know the spacing you can predict where they will be, meaning that you can avoid putting your holes for the downlighters within around 6 inches of a joist, ideally.

Mark the ceiling at the centre of each spot. When you are happy with the positioning you are ready for the next step.

2 – Cutting the Holes for Downlights

Once you know where each downlighter will be fitted, then you should drill a small pilot hole. Go above the ceiling to confirm that each one will be clear to cut or drill the larger hole for the down lighter without hitting anything. The light from below should shine through, or you might need to stick something through so you can see the position of each one.

If you can get access to the ceiling from above you will need to clear the area by sticking a piece of bent wire through the pilot hole and twisting it around to feel for any unseen obstructions.

There are three key dimensions that you need to make a note of for fitting your lights:

1. Cut out – this is the size of the hole you need to cut in the ceiling to insert the light. This dimension is normally provided on the box containing the light
2. Height – this is the height of the lighting unit; there are low profile lights if you have limited space in your ceiling
3. Overall Diameter – (OS) this is the size of the light that will be visible on the ceiling

Typically domestic downlights use a cut out of 80mm, although there is a huge range from anything from 30mm to 200mm and more. Mini downlighters usually require cut outs in the region of 60mm, and under cabinet lights are less than 50mm.

The other key measurement for fitting is the height as the space above the ceiling will determine what you can use. Larger lights with larger cut outs will have a greater height. Typical heights for 80mm cut out lights are in the region of 75 – 110mm typically, although it is possible to find “low profile” models should space be really tight. Under cabinet downlights are often designed to be surface mounted and therefore have heights of around 15mm.

With so much variety you simply have to check the design that you want and ensure that the measurements are going to fit in your ceiling. If it doesn’t there is sure to be one that will.

There will probably be instructions with the downlighters kits that you buy so you should follow these. Often there is a template to mark out the size of the circle you need to cut out, however if not you can either draw the right size with a compass and pencil or use the correct sized hole saw guided by your pilot hole.

Top Tip: Often you will have yet to have plastered the ceiling, so drawing on it is no problem as the plaster will cover the mark you make.

Once the holes are marked you are ready to cut them out; you can do this by hand using a Plasterboard or Pad Saw or you could use a hole saw. You can find a range of hole saws here.

Top Tip: Use a cheap or old hole saw as drilling into plasterboard is not good for them.

A good idea to use a dust-catcher when drilling holes above your head. It both saves dust going in your eyes and onto the floor.

Now you will have your holes it is time to connect up the electrics.

3 – How to Wire in Downlights

The next step is to wire in the lights. Remember the safety aspects of working with electricity and ensure that the circuit is isolated; test and double test that it is not live before you start.

Downlights are wired on radial circuits which mean that they are all in a line. You will need to run the appropriate cable from the switch or ceiling rose to the first light, and then cable will be run on to the next light and so on until the last light in the circuit. For more information about how to wire the lights see our project on wiring lighting circuits.

Use a connector (chocbox) to connect the wiring for the lights as this is generally the easiest way to connect cables.

At this point you will have the connected downlights hanging from the ceiling. All that remains is insert the light into place.

Inserting Downlights into your Ceiling

This is the easy bit!

Generally there are springs on the side of the light unit which is going to be recessed into the ceiling. Squeeze these in so that the light can be pushed up into the hole that you have cut out.

As the light slides into the hole, the wire catches will catch on the ceiling and force out the springs so that they push down on the upper side of the ceiling boards holding the light unit in place.

Choosing Your Recessed Down Lights

There are a number of things to consider when selecting downlights. We will cover the main questions that you will probably be asking yourself when you’re selecting your lights:

Should you use 12 Volt or 230 Volt lights?

It used to be popular to use 12 V lights in kitchens and bathrooms because they offered a better light and also had the benefit of being lower voltage, however they need a transformer to step the voltage down which will get hot so needs to be ventilated.

With the advent of LED lights, there is no need to go for 12 volt lights as LEDs come in all the different light intensities and colours you could want and have dimmable versions, so there is no real benefit to using 12 Volt anymore. It is less complicated to simply stick with 230 Volt.

Which is Best for Downlights, LED or Halogen?

Halogen lights were a huge technological leap forward in their day, however they are only about 30% more efficient than old fashioned incandescent bulbs and will only last about 2 years (based on 3 hours usage everyday). They also get hot so consideration needs to be given to ventilation.

LED lights offer the same light quality, are 90% more energy efficient than old fashioned bulbs, and will last of 25 years when used 3 hours a day. They are a little more expensive, but well worth the extra cost. For us it is LEDs everytime.

Should the Downlights be Fire Rated?

As we mentioned above, the ceiling is an important fire barrier to slow the spread of a fire to upper floors. Peppering this with holes will not help, so you should fill these holes with fire rated lights and in many cases the regulations will ensure you have to – see more information in the Building Regulations Approved Document B all about fire safety.

What Other Ratings for Downlighters do you Need to Consider?

You must consider the safety zones in bathroom where the lights are going to be fitted (which you can find all about here) as you will need to use IP rated lights in these zones. You need to ensure that you are using the right IP rated light in the zone you are planning to have the lights fitted.

There are acoustic rated downlights which you can consider using if there is a problem with noise from the floor above.

Are Integrated Downlights Better or Worse Than Standard Downlights?

Integrated downlights are lights where the blub is fitted inside them and cannot be removed – integrated. Because LED bulbs have such a long life it is considered that they will outlast the life of the lightitself, or at least provide sufficient life.

With standard downlighters you can change the bulb as normal. Which offer more flexibility should you need to, or if you want to change to a different tone light.

The big danger is that if one light fails and you cannot get a matching replacement, if the model has been discontinued for example (which might well happen in the long life of these lights), then you have to replace the whole lot if you want them to match.

Fitting, replacing or adding downlighters to your ceiling is a job that can easily be done yourself. Even if you decide to leave the electrical work to an electrician, which is a good idea if you’re unsure or a must if you are working in the kitchen or bathroom, you can get a fair amount of the work done saving yourself the labour cost of a skilled tradesman.

All project content written and produced by Mike Edwards, founder of DIY Doctor and industry expert in building technology.