UK House Extension Episode 7-Lighting
Updated: Apr 28, 2022
Lighting is a wide topic and largely driven by personal taste for ambience and mood lighting. Here we would try to limit the scope by just focussing on standard lighting with recessed LED downlights which is the most common type of LED lights
Big question is what type and how many you need?
The first important factor in choosing LEDs is the colour temperature of the LEDs which ranges from Warm White-2700k to Daylight Cool White-6500k. The older halogen or incandescent bulbs produced between 2700k and 3000k which was on the warmer end of the spectrum. Generally, for a modern kitchen you may consider 4000k which is around the cooler side of the spectrum. If you go for expensive smart LED bulbs then you may be able to control the spectrum via smartphone
Next, you will need to decide if you want to be able to control the brightness of your lights in which case you may want to buy dimmable LEDs. You cannot buy non dimmable LEDs and then connect them to a dimmer.
Now the main question, how many you need and where will you place them in the ceiling.
Generally, for kitchen area a task light level of 300 lux at a surface height of 0.75m is considered a good ballpark. There are various websites available which can help you calculate the number of LEDs required. A few are listed below
Our kitchen area is 5m x 4m with a 2.4m ceiling height. We have a roof lantern 2m x 1m in the middle. Based on the calculators for a 5W 500 Lumen 4000k LED below was our layout.
We decided to split our lights in 2 circuits with 1 circuit controlling 4 leds in the centre and the other controlling the remaining lamps. This allows us to control the LEDs depending on how bright it is outside with added control via dimmer. You can decide as many circuits which suit your needs.
We also adjusted the distance from the wall slightly to account for kitchen cabinets. We also put an extra one above the sink. Symmetry is good but it doesn't matter that much so an extra LED in key areas will always help. Working with the builder with a diagram helps in making sure there is no ambiguity.
For our Living room we went for 5W 500 Lumen 3000k Warm white LEDs with layout as below. We had two circuits, one for the bank of LEDs and the other for a centre decorative ceiling light.
In addition to choosing the LEDs you need to choose the fittings or Downlights in which these LEDs will go. You will have to decide depending on building regulations if you are required to use fire rated downlights. When a hole is created in the ceiling it creates an outlet for fire to travel upwards potentially to the floors above. Fire rated downlights seal off the hole and help slow down the spread of fire. General recommendation is to go for Fire rated downlights if possible.
Next you will need to decide the IP ratings for downlights. Generally, you do not need to worry about these for kitchen but for bathrooms an IP65 rating will be a good choice unless you are fitting lights inside the bath tub. Do read up on this before deciding.