I've a feeling there's something building regs wise for being able to monitor consumption separately for "lighting" and "power" that usually drives split metering in commercial premises over a certain size, I'd check on the details though.

   - Andy.

I checked APDL and it states the following:

Energy submetering systems should be installed in new buildings, or when fixed building services
are provided or extended in an existing building, and should meet all of the following requirements.

a. The various end-use categories, such as heating, lighting and cooling, should be submetered in
such a way that at least 90% of the annual energy consumption of each fuel can be assigned to
an end-use. Detailed guidance on how to achieve this is given in CIBSE’s TM39.

"Fixed building service in an existing building" - some services remain in place some new. The way I read that is if tenant load doesn't make up 90% landlord needs to be sub-metered too? 

Indeed there is a need to be able to record the lighting consumption, since 2021

Energy submeters
5.17 Energy submetering systems should be installed in new buildings, or when fixed building services
are provided or extended in an existing building, and should meet all of the following requirements.
a. The various end-use categories, such as heating, lighting and cooling, should be submetered in
such a way that at least 90% of the annual energy consumption of each fuel can be assigned to
an end-use. Detailed guidance on how to achieve this is given in CIBSE’s TM39.
b. Metering should enable the comparison of forecast energy use and in-performance energy and
facilitate energy reporting. This can be demonstrated by basing the submetering strategy on a
design-stage energy forecast for the building, using one of the methodologies in paragraph 9.4.
c. Metering should allow the energy use of different tenants within the building to be separately
monitored.
d. The outputs of any renewable systems should be separately monitored.
e. In buildings with a total useful floor area greater than 1000m2, automatic meter reading and data
collection facilities should be installed

and also

 Part L 2021 requirements for light metering:-

 6.61 - General lighting and display lighting should be metered by one of the following methods.

1. Dedicated lighting circuits with a kWh meter for each circuit.
2. Local power meter coupled to or integrated in the lighting controllers of a lighting management system.
3. A lighting management system that can both: i. calculate the consumed energy ii. make this information available to a building management system.

in fact (I must have slept through that ;-)  ) it was discussed here (as in here). however I'd not expect a large no of supplies and full current meters just a row of DIN rail indicators examples   at the most if this function is not already being included already as part of some integrated building control system.

Mike

Thanks Mike, those were my thoughts too. Some boards were being kept with a single meter which would not be in line with the latest changes

Thanks Mike, those were my thoughts too. Some boards were being kept with a single meter which would not be in line with the latest changes