@vinoandbrie Have a look at Drayton Wiser - I have a big house and I have smart TRVs on all the radiators. It means that if I am the only person in the house, I can heat the room I am in, but the other radiators won't come on.
(When its cold) So for instance, I work in the backroom of the house, the radiator will come on in here whilst working.
At about 3pm I have it set so the living room and DS bedroom come on. They turn off at 7pm as DS room will be warm enough and he has wool duvet/hot water bottle. My bedroom gets heated by downstairs, so comes on for an hour before bedtime. Then the whole house heats from 6am to 7am and then turns off except where I am working.
Now, this actually saved me 60% energy usage over just all radiators coming on. I've had this system for a few years now. I even have it set so if no one is in the house it all just turns off.
At the moment as its warmer, I've just set the whole system to off, unless we have freak weather and it dips below 13degrees inside in which case it will fire up.
I will probably make some adjustments in the winter.
With regards to energy in terms of electricity, all our big devices are plugged into smart plugs - when I say Alexa goodnight, she turns them all off. All of our bulbs are Hue Bulbs, they're set to 60% dimness. Bathroom lights are motion sensored so if there is no movement within 3 minutes they turn off as the boys kept leaving the lights on. Same in the kitchen which you walk through to get to the back bathroom and my office.
I love smart stuff and did a lot of it diy, my energy bill dipped, I think the cost of setting it up evened out after two years maybe?