I was going to say Sonos and then got to your budget.
Deos the 250 budget just for devices to control existing equipment, or is it 250 for speakers plus amps/whatever plus controllers?
Home automation is the residential extension of building automation.
It is automation of the home, housework or household activity.
Home automation may include centralized control of lighting, HVAC (heating, ventilation and air conditioning), appliances, security locks of gates and doors and other systems, to provide improved convenience, comfort, energy efficiency and security.
Warning: Working with electricity can result in injury, property damage, or even death if it is not done properly. Please keep this in mind while assisting others. If you are not sure about what you are doing, hire a licensed professional.
I was going to say Sonos and then got to your budget.
Deos the 250 budget just for devices to control existing equipment, or is it 250 for speakers plus amps/whatever plus controllers?
I would look for https://www.picoreplayer.org/
I am thinking of making something similar, so I see it as piCorePlayer running on Raspberry Pi Zero 2 W with some DAC hat.
You can squeeze Pi Zero 2 W + DAC in £50 (give or take).