Part L is divided into four individual documents:

1) Part L1A

2) Part L1B

3) Part L2A

4) Part L2B

 

The requirement for Part L and its implementation requires a breakdown of the energy consumption of different categories, lighting, ventilation, etc. This so the client or building owner/occupier can aim to reduce their energy consumption. To achieve this, it is suggested that at least 90% of each fuel consumption, in this case, electricity is to be accounted for.

This calling for all distribution boards greater than 50kW to be individually metered, which effectively due to most type B Distribution Boards being 100A or greater, this calls for pretty much all of them to be metered and is generally good practice. P.S lighting and power should be metered separately.

 

It is also detailed that motor control centres feeding pumps or fans of loads greater than 10kW must be metered separately and also boilers over 50kW, chillers over 20kW and electric humidifiers over 10kW.

 

Essentially giving a breaker down on what and what not to meter, therefore giving a solution to aim to reduce energy costs and increase energy efficiency, as is the nature of the regulation.