Contemporary low voltage garden lighting requires just three parts: a 12v transformer to provide a safe low voltage power supply; a cable to distribute the power supply to where it’s needed; and the garden light fittings.

First though it is vital to select which type of lighting (traditional incandescent bulbs or LEDs) and to gauge the rating of the transformer necessary to run the lights (which depends on how bright they are and how many are required).

We will cover the differences between the two types of system (and how to combine them) later, but both otherwise follow exactly the same basic principles.

Calculating the size of transformer required is simply a matter of counting up the wattages for all the actual lights (so, 3 x 10 watt deck lights plus 2 x 20 watt standard lanterns comes to 70 watts for example) and tells you what rating of transformer you need to purchase.

The transformer input is connected to a mains outlet and must therefore be placed inside. The transformer output is then connected to the cable which then leads outdoors.