Grow room setup and power consumption in UK

I currently have a 2.4m x 1.2 m tent but I am looking to expand into the attic space and have either a massive flower room or a complete set up from clone to flower. My attic space is huge and I could fit many lights in there but what can I do about power consumption?
Also interested to hear peoples opinions on whether I should have a clone/mother room, veg room and flower room or just have 1 flower room.

What can you do about power consumption?

Firstly. Get the best deal you can on electricity and pay your bill.
Do not try and rig your meter because the big dog power companies will prosecute you to the full extent of the law. Far harsher than a cultivation charge.

If you have the money you can reduce your consumption by using high efficient LED, note the words "high efficient" Not all LEDs are more efficient.

Good ones cost money, save you around 30-40% on power usage by creating more light per watt therefore using less overall power.

Or invest in solar or other forms of power you can create to reduce your need for electricity.

Growing in attics takes money. You want it fully insulated or its a terrible environment , too cold in winter and far too hot in summer. People have died in attics due to the crazy heat in summer.

You still need to vent that attic space the same as any other to reduce heat, humidity and keep co2 levels up unless of course you want a fully sealed room running co2 and air conditioning.

Think about how you will create a stable environment that you can control.